Ewan Wins Stage and Bernal Makes History!

Caleb Ewan won his third stage in this year's Tour de France.  The loops around Paris are so much fun to watch at the end of the final stage.  Ewan just burst through at the end to win the stage (click on image for a larger view).

You can see Ewan on the far left in red and white.  You can also see Egan Bernal with the yellow jersey in the center of the screen capture.  He's about to come in 29th in the stage, but, more importantly, he's about to make history as the first Colombian to win the general classification at the Tour de France.  Before getting to Bernal, check out how our prediction fared today.

• Stage 21:  3h 04' 08", 3h 06' 05" (prediction), 01' 57" slow (1.06% error)

We've done well on the last stage in the past, and I'm thrilled with today's result.  Ewan's average speed is given below.

• Stage 21:  11.59 m/s (41.71 kph or 25.92 mph)

The ceremonial aspects of the stage make it a challenge to model.  Just after the stage commenced, Egan Bernal had a wonderful moment with Julian Alaphilippe (click on image for a larger view).

And it wasn't long afterwards that Bernal partook of the tradition of drinking champagne (click on image for a larger view).

Bernal won the Tour de France with a time of 82h 57' 00".  Given the two shortened stages in the Alps, the total distance came to 3365.8 km (2091.4 mi).  I'd have to bike from my office at the University of Lynchburg to Yellowstone National Park to match that distance.  What I couldn't possibly do is bike that distance in a three-week period while averaging 40.58 kph (25.21 mph) in the saddle!

The post-race ceremony was moving to say the least.  Julian Alaphilippe most definitely deserved the most combative prize.  It was a joy to watch Alaphilippe over the past three weeks.  He made France very proud.  Peter Sagan won his record seventh green jersey.  Romain Bardet recovered from a rocky start to win the polka dot jersey.  Besides the yellow jersey, Bernal won the white jersey -- and he's eligible to win it for three more years.  Check out the jersey winners (click on image for a larger view).

Bernal's muli-language speech on the podium was beautiful.  He stood with teammate Geraint Thomas, who came in second, and Steven Kruijswijk, who came in third (click on image for a larger view).

Can Bernal win another Tour de France?  At just 22 years old, he certainly appears to have a bright future!

Posting predictions on my blog has always added to the fun of watching the Tour de France for me.  I thank two of my research students, Carl Pilat and Noah Baumgartner, who both did excellent work this summer.  The real work always comes after the Tour de France ends when post-race analysis begins.  Stage 7 was our one really bad prediction.  Of the 20 stages we could predict, we hit 14 of them to better than 6%, including eight of them to better than 3%.  I'm on holiday beginning tomorrow.  I'll likely write one more Tour de France blog post after my return.

The Shark Takes Shortened Stage 20!

Vincenzo Nibali rode with gusto up to Val Thorens and held off his competitors in the final kilometer to win the penultimate stage of this year's Tour de France.  Check out Nibali after crossing the finish line (click on image for a larger view).

It was great watching the world's best on the final climb of this year's race.  The last two stages in the Alps got blasted by the weather, but there was still a lot of drama.  I wish I had a prediction to compare to today's result, but I simply didn't get a chance last night to analyze the new stage route.  Below is Nibali's winning time.

• Stage 20:  1h 51' 53" (actual)

His average speed is given below.

• Stage 20:  8.86 m/s (31.91 kph or 19.83 mph)

That average speed happens to be about 2 kph greater than the maximum estimated by the race organizers.  Cyclists were definitely outputting more power this year than the ones we've modeled in the past.

This will be an historic Tour de France as Egan Bernal will become Colombia's first general classification winner.  Oh, by the way, Bernal is just 22 years old.  This kid could dominate cycling for many years to come.  Last year's winner, Geraint Thomas, will finish second this year.  That gives Team Ineos (formerly Team Sky) the top two spots on the podium tomorrow.  Not only did the team do well without Chris Froome, they will have seven of the last eight Tour de France winners, including the last five in a row.  That's domination!  Dutch cyclist Steven Kruijswijk will finish third overall tomorrow.  Julian Alaphilippe, who stole the hearts of French cycling fans, will finish fifth.  What he did on Stage 3 and on the individual time trial in Stage 13 will never be forgotten.

Tomorrow's final Tour de France stage is mostly ceremonial, but the sprinters will go for the stage win as they near Paris.  The 128-km (79.5-mi) flat stage commences in Rambouillet and then takes riders northeast to the Champs-Élysées in Paris.  Our prediction is given below.

• Stage 21:  3h 06' 05" (prediction)

I can't wait to see history get made tomorrow!

Stage 19 Winner is ... ICE and MUD???

Each year's Tour de France brings me something new and exciting.  I'm not a lifelong viewer of the Tour de France, but in the 15 or so years that I've followed the world's most famous bike race with the interest of a physicist who modeled the event, I've never seen anything like what happened today.  As I wrote yesterday, and as any fan of the race probably suspected, the yellow jersey was attacked on the climb to the summit of Col de l'Iseran.  Julian Alaphilippe was giving it his all, but Colombian Egan Bernal simply dominated the climb to highest point (2270 m or 9088 ft) in this year's Tour de France.  I had no idea when I grabbed the screen capture of Bernal reaching the summit first that the summit would end up being the finish line for today's stage (click on image for a larger view).

Bernal began the descent as the virtual race leader.  Alaphilippe was hoping to make up time on the descent because he is an incredibly skilled downhill racer.  As the screen capture shows, he was a little more than two minutes behind Bernal (click on image for a larger view).

Alaphilippe then began flying on the descent, hoping to shave seconds off Bernal's lead (click on image for a larger view).

But then the stage was stopped!  Just passed one of the tunnels near Val d'Isère, a huge amount of ice, water, and mud had flowed onto the road (click on image for a larger view).

That didn't look as bad until the helicopters moved down the road (click on image for a larger view).

Race officials absolutely did the right thing.  Cyclists were approximately 10 km from what you see above, and there is no way the road would have cleared in just a few minutes.  Water and mud were still streaming down the hillside.  The plow was engaged in a seemingly futile attempt to clear water.

Alaphilippe was visibly angered by what happened.  He may have shaved several seconds off Bernal's lead during the descent, but would he have been able to do the same on the final climb?  Alaphilippe could have lost even more time instead of being 48 seconds behind Bernal going into the final mountain stage.

As for a model comparison, the best I can offer is the time our model predicted to the summit of Col de l'Iseran.  Entering today's stage, Egan Bernal had an accumulated time of 75h 20' 19".  He is now listed as leading the general classification at 78h 00' 42", but he earned an 8" time bonus today.  That gives Bernal a time of 2h 40' 31" to the point where the race stopped.  My model prediction to that point is compared to Bernal's time below.

• Stage 19:  2h 40' 31" (actual), 2h 49' 12" (prediction), 08' 41" slow (5.41% error)

That's the best I can do for today.  Would our model have caught up to cyclists on the final climb?  I've no idea, and I won't speculate.  I'll have to stick with what you see above.  Bernal's average speed to the stoppage point is given below.

• Stage 19:  9.26 m/s (33.32 kph or 20.71 mph)

Tomorrow's Stage 20 begins in the Olympic town of Albertville.  Cyclists will then travel 130 km (80.8 mi), first east, then south to the ski resort of Val Thorens.  After an early sprint, riders will have a category-1 climb to the 1968-m (6457-ft) peak of Cormet de Roselend.  The big finale will be the 33.4-km (20.8-mi) Hors catégorie climb to an elevation of 2365 m (7759 ft) at the finish line in Val Thorens.  Our prediction is given below.

• Stage 20:  3h 39' 46" (prediction)

How today's events will affect tomorrow's stage is anybody's guess.  Our model certainly can't predict that!  It will be exciting to see if Colombia will get its first Tour de France winner.  It's too bad that Thibaut Pinot had to abandon the race today with a torn quadriceps muscle while fifth overall in the general classification standings.  The hopes of everyone in France now sit squarely on Julian Alaphilippe.

Quintana Attacked Col du Galibier and Won Stage 18!

I've been rooting for Nairo Quintana for years.  The Colombian is a great climber, and he showed what he can do today.  He crossed the finish line in the rain and with blood on his jersey, possibly from a nosebleed while at high altitude (click on image for a larger view).

He attacked on the Col du Galibier with about 26.3 km (16.3 mi) left in the stage, and nobody could keep up him.  The riders he left seemed almost stunned at how Quintana burst forward.  Check out where Quintana made his move (click on image for a larger view).

You can see Quintana in his blue Movistar Team jersey.  He owned the final 7.5 km (4.7 mi) of the climb and easily crossed the peak first (click on image for a larger view).

I was not only thrilled for Quintana, I was thrilled for our model.

• Stage 18:  5h 34' 15" (actual), 5h 38' 19" (prediction), 04' 04" slow (1.22% error)

We nailed the first stage in the Alps!  Quintana's great climb led to a top-notch average speed.

• Stage 18:  10.37 m/s (37.34 kph or 23.20 mph)

It was a joy to watch Quintana on that final climb.  He vaulted from #12 to #7 in the general classification, now 03' 54" behind Julian Alaphilippe.  The race leader passed his first big test today, only sacrificing five seconds on his lead.  Expect attacking tomorrow on a relatively short 126.5-km (78.6-mi) mountain stage.  Riders will not want to leave everything to the final mountain stage.

Stage 19 begins in the commune of Saint-Jean-de-Maurienne.  Cyclists will head mostly east and mostly uphill for the first 70% of the stage.  That major uphill effort will culminate in the Hors catégorie climb to the 2770-m (9088-ft) peak of Col de l'Iseran.  The stage finishes with a category-1 climb into Tignes.  Our prediction is given below.

• Stage 19:  3h 32' 37" (prediction)

If a few riders are able to maintain a lot of pressure on the yellow jersey, we could be a tad slow.  I'm anxious to see more Alps climbing tomorrow!

Trentin Blasts his way to Stage Win!

Matteo Trentin broke off the lead group before the final climb and powered his way to the stage win.  The leaders raced at a scorching pace today.  I knew the general classification leaders would hold back today, but we ended up modeling the peloton's pace, not the winner's pace.  I'm simply amazed by the power output from today's elite cyclists.  Before getting to our prediction, check out Trentin crossing the finish line all alone (click on image for a larger view).

Okay, now for the comparison.

• Stage 17:  4h 21' 36" (actual), 4h 42' 42" (prediction), 21' 06' slow (8.07% error)

What's bizarre about what our model did today is that it nearly predicted the peloton's arrival to zero error.  The peloton came in 20' 10" after Trentin.  In other words, our model missed the peloton's time by just 54".  But we want to be able to model the winner, not the peloton!

Despite our model being slow today, it was great watching Trentin's ride.  Below is the moment when today's stage was won (click on image for a larger view).

I got that screen capture when Trentin broke off from the lead group and took a peek back to see if anyone was chasing him.  He accelerated past 60 kph (37 mph) to get in front.  The race was over at that point.  Check out Trentin's average speed.

• Stage 17:  12.74 m/s (45.87 kph or 28.50 mph)

The winning cyclist was once again about 2 kph faster than what the Tour de France organizers estimated for the top speed of the day.

The Tour de France will be decided over the next three stages in the Alps.  Tomorrow's Stage 18 will be something to watch!  Commencing in the commune of Embrun, cyclists will ride 208 km (129 mi) mostly north to Volloire, which is almost to the border with Italy.  Riders will climb to the 2109-m (6919-ft) peak of Col de Vars before two facing two Hors catégorie climbs.  The first is to the 2360-m (7743-ft) peak of Col d'Izoard; the second is to the 2642-m (8668-ft) peak of Col du Galibier.  The descents off each mountain will lead to some blistering speeds.  I hope there are several riders coming off the final climb because that would make for a spectacular downhill sprint to the finish line.  Our prediction is given below.

• Stage 18:  5h 38' 19" (prediction)

The Tour de France has befuddled me a bit this year, sometimes in exciting ways.  Regardless of how our model performs tomorrow, I'm anxious to see the monster climbs in the Alps!

Caleb Ewan Sprints to Second Stage Win!

Caleb Ewan's burst of acceleration inside 100 m left in today's stage put him in front of several of the world's best sprinters.  In fact, 48 of 162 cyclists (about 30%) who finished today's stage earned the same time Ewan achieved.  But Ewan got all the glory after coming in first (click on image for a larger view).

Ewan is in red and white, about to cross the finish line at a blistering 66 kph (41 mph).  Our model did wonderfully today.

• Stage 16:  3h 57' 08" (actual), 3h 53' 10" (prediction), 03 58" fast (-1.67% error)

That's what I like to see!  Check out Ewan's average speed.

• Stage 16:  12.44 m/s (44.78 kph or 27.83 mph)

Tomorrow's Stage 17 is hilly and 200 km (124 mi) long.  Riders begin at Pont du Gard and travel northeast to Gap, where the Alps will be waiting for them.  Much of the first half of the stage is uphill.  Our prediction is given below.

• Stage 17:  4h 42' 42" (prediction)

Even if the leaders in the general classification lay back a bit in preparation for the Alps, I hope to see the sprinters flying downhill at the end.

Stage 16 Prediction

Stage 16 is an interesting flat stage because it begins and ends in the same city.  The Tour de France cyclists are resting in Nîmes today, which is the city where tomorrow's Stage 16 begins and ends.  The 177-km (110-mi) stage loops counterclockwise to the north.  Our prediction is given below.

• Stage 16:  3h 53' 10" (prediction)

Will the general classification contenders ride safely tomorrow, staying in a leisurely-moving peloton, all looking to get the same time?  It wouldn't be the worst strategy, given the later stages in the Alps.  It will be interesting, though, to see if any of the teams try to push Julian Alaphilippe.

Brilliant Ride Wins Stage 15 for Simon Yates!

This year's elite climbers are definitely outperforming our model.  They are outputting more power than they did last year.  Simon Yates rode with great form and rode with aggression on the final climb.  I'll start with the screen capture I got when Yates crossed the finish line (click on image for a larger view).

But that's not when I jumped out of my office chair.  Yates and Simon Geschke were leading the race up the final climb when, with about 8.7 km left in the stage, Yates attacked with passion (click on image for a larger view).

You can see Yates near the motorcycle and Geschke, who finished 25th today, permanently dropped.  There was so much attacking and cracking on the final climb that Yates kept up a torrid pace.  Julian Alaphilippe, who climbed without help from teammates and came in 11th today, lost time on his yellow-Jersey lead.  Thibaut Pinot came in second today and jumped up to fourth in the general classification, just 01' 50" behind Alaphilippe.

Descent racing was spectacular.  Speeds were high, despite mist making visibility tough for the cyclists (click on image for a larger view).

Pace was fast today and I knew we'd be slow with our prediction.  We needed more than 4% more power on our model cyclist; 42 riders (out of 164, or 25.6%) beat our predicted time today.

• Stage 15:  4h 47' 04" (actual), 5h 03' 05" (prediction), 16' 01" slow (5.58% error)

I hope we can cut that error in half when the riders get to the Alps.  Yates's average speed on his second stage win in the year's Tour de France is given below.

• Stage 15:  10.74 m/s (38.67 kph or 24.03 mph)

That is truly an impressive average speed on a stage like today's stage.  That maximum anticipated average speed by the Tour de France organizers was 37 kph.  The athletes are clearly outperforming exceptions on many fronts.  It's impressive to watch!

Tomorrow is the second and last rest day.  Cyclists will rest in Nîmes, which is nearly on the southern coast with the Mediterranean Sea.  They'll need to rest because after tomorrow, they'll have a flat stage and then a hilly stage before three brutal mountain stages in the Alps.  Those three stages have four Hors catégorie climbs in them, compared to just one they endured in the Pyrenees.  The race will surely be won in the Alps.  I'll be back tomorrow with our Stage 16 prediction.

Pinot Dominates Col du Tourmalet!

Thibaut Pinot pulled ahead of fellow Frenchman Julian Alaphilippe in the final 250 m to win today's Stage 14 of the Tour de France.  Alaphilippe extended his general classification lead over Geraint Thomas to 02' 02".  Pinot moved from seventh to sixth overall, now 03' 12" behind Alaphilippe.  The French have to be thrilled with what's happening in this year's Tour de France.  Does Pinot look happy winning today's stage? (click on image for a larger view)

I always wonder how much of the scenery the cyclists take in.  They concentrate and focus on their riding, and they've ridden these routes before, but for someone like me, the top of Col du Tourmalet looks so amazing that I'd have trouble concentrating and focusing! (click on image for a larger view)

It was the 83rd time the Tour de France came to Col du Tourmalet.  I was watching in my office as some of the world's best cracked on the final climb.  The mountain split up the peloton and only the truly elite riders powered up for the top of stage standings.  Check out how our prediction fared.

• Stage 14:  3h 10' 20" (actual), 3h 19' 37" (prediction), 09' 17" slow (4.88% error)

I was hoping we could do just a tad bit better, but I'll take that error.  Twenty-six cyclists beat our predicted time today.  Climb strategies and cyclists' legs are unpredictable.  Check out Tim Wellens collecting 10 more points for his polka-dot jersey as he was the first atop Col du Soulor (click on image for a larger view).

Wellens did a great job pinning 2014 winner Vincenzo Nibali against the fans just before reaching the top.  I love watching the Shark on the descents.  Nibali kept the pace fast before reaching Col du Tourmalet, but fell back on the climb and finished 74th today.

At the end of the stage, fans were going crazy, crowding the riders (click on image for a larger view).

Pinot's average speed is given below.

• Stage 14:  10.29 m/s (37.04 kph or 23.02 mph)

That's impressive!

Tomorrow's Stage 15 begins in the commune of Limoux.  The 185-km (115-mi) mountain stage takes riders west into the Pyrenees. Top elevation will be the category-1 climb to the 1517-m (4977-ft) peak of Port de Lers.  That will be followed by a category-1 climb up Mur de Péguère.  The stage ends with a category-1 climb up Foix Prat d'Albis.  Tomorrow's stage is longer than today's, and it has more climbing.  Our prediction is given below.

• Stage 15:  5h 03' 05" (prediction)

It will be hard to beat today's action.  I hope tomorrow's stage delivers the goods!

Alaphilippe is Last Out and Fastest!

Julian Alaphilippe was the last rider released in today's individual time trial.  The yellow jersey wearer had the opportunity to win a stage on the 100th anniversary of the yellow jersey.  Thomas De Gendt spent much of the time trial in the hot seat.  But Geraint Thomas came in 22" quicker, and then all eyes turned to Alaphilippe.  The Frenchman gave it his all during the final kilometer and came in 14" quicker than Thomas.  Check out Alaphilippe's exertion at the finish line (click on image for a larger view).

We had our best prediction today.

• Stage 13:  35' 00" (actual), 34' 52" (prediction), 00' 08" fast (-0.39% error)

I'm most definitely happy with that!  Check out Alaphilippe's average speed.

• Stage 13:  12.95 m/s (46.63 kph or 28.97 mph)

That's pretty fast!  Look at Alaphilippe's great form on the bike near the end of the stage, where he kicked it up a notch and took control (click on image for a larger view).

You can see the speed there, which is 54 kph (34 mph).

Time trials are so much fun to watch, especially for a physicist.  The tailor-made skin suits are crafted to exactly fit each rider.  The goal, of course, is to reduce air drag.  Several riders didn't push very hard today, likely wanting to save energy for what's awaiting them in the next two stages before the second and final rest day.  Who else but Peter Sagan would be popping a wheelie on the stage? (click on image for a larger view)

He definitely gave fans something to smile about!

There were some unfortunate crashes during the time trial.  Stefan Küng crashed early in the route.  Maximilian Schachmann crashed and barely made it across the finish line.  I was so anxious to see what time Wout van Aert would get.  I was hoping he could sneak in under 35'.  But he had an awful crash with just over 1 km left in his ride (click on image for a larger view).

Tomorrow's Stage 14 looks to be a grueling mountain stage.  Beginning in the commune of Tarbes, riders will meet a category-1 climb in the middle of the stage.  They'll ride across the 1474-m (4836-ft) peak of Col du Soulor in the Pyrenees.  The 117.5-km (73.01-mi) stage ends with an Hors catégorie climb to the 2115-m (6939-ft) peak of Col du Tourmalet.  Our prediction is given below.

• Stage 14:  3h 19' 37" (prediction)

I can't wait to see that climb to the finish line!

Simon Yates Takes a FAST Stage 12!

Brit Simon Yates out-sprinted Pello Bilbao of Spain and Austrian Gregor Mühlberger to win a very fast Stage 12.  It was a lot of fun watching the three of them help each other on the rapid descent off La Hourquette d'Ancizan.  They alternated lead position and helped draft each other.  That kept the pursuers at bay.  Check out Yates coming in just ahead of Bilbao and Mühlberger (click on image for a larger view).

Bilbao is on the right; Mühlberger is on the left.  I was stunned that the winning time came in under five hours.  Our prediction wasn't great.

• Stage 12:  4h 57' 53" (actual), 5h 23' 17" (prediction), 25' 24" slow (8.53% error)

We were nearly perfect on the first mountain stage, which was the grueling Stage 6 with its category-1 climb finish.  That stage was 49 km (30 mi) shorter than today's stage, but the top cyclists today output 13% more power today than during Stage 6.  Were they holding back on Stage 6, going crazy today, or is there a better explanation?  This really has been a fascinating year for modeling the Tour de France!  Yates's average speed is given below.

• Stage 12:  11.72 m/s (42.20 kph or 26.22 mph)

I love watching the mountain stages.  Check out Tim Wellens crossing the top of Col de Peyresourde (click on image for a larger view).

A little later, Simon Yates and his two finishing companions were first atop La Hourquette d'Ancizan (click on image for a larger view).

On the first big descent, speeds reached over 90 kph (56 mph).  I just can't imagine going that fast on a bicycle.  And of course scenery was spectacular in the Pyrenees.  Check out one of the valleys on the final descent (click on image for a larger view).

The Tour de France is quite an advertisement for visiting France!

Tomorrow's Stage 13 is an individual time trial.  The 27.2-km (16.9-mi) route begins and ends in Pau.  Riders will loop south and then back north during their rides.  Our prediction is given below.

• Stage 13:  34' 52" (prediction)

Will there be a shakeup in the general classification tomorrow?

Ewan Out-Sprints Groenewegen for Stage 11 Win!

Though the stage wasn't quite as fast as I thought it could be, Stage 11 gave fans yet another great day of Tour de France racing.  Aussie Caleb Ewan just barely finished ahead of Dylan Groenewegen for the stage win (click on image for a larger view).

I was a split second early with my screen capture, but you can see Ewan in read and white leaning just ahead of Groenewegen in yellow and black.  See how our predication fared.

• Stage 11:  3h 51' 26" (actual), 3h 39' 54" (prediction), 11' 32" fast (-4.98% error)

I thought we'd be a bit closer, but racing in the first half of the stage was slower than I anticipated.  But check out Ewan's average speed.

• Stage 11:  12.03 m/s (43.30 kph or 26.90 mph)

Not too shabby!  I suspect the cyclists will be somewhat rested for tomorrow's Stage 12, which is a 209.5-km (130.2-mi) long mountain stage.  Picking up in Toulouse, where Stage 11 ended, cyclists will travel southwest into the Pyrenees.  Category-1 climbs up Col de Peyresourde and La Hourquette d'Ancizan will highlight the stage.  The stage ends with what could be a ferocious downhill sprint into Bagnères-de-Bigorre.  Our prediction is given below.

• Stage 12:  5h 23' 17" (prediction)

I'm anxious to see the world's best cyclists climb those two mountains tomorrow.  Will there be a shakeup in the general classification?

Stage 11 Prediction

Tour de France riders are resting today.  Tomorrow's Stage 11 is an interesting stage.  It begins in Albi, where riders are resting.  The 167-km (104-mi) flat stage will take the cyclists around a loop to the west, followed by a stretch to the south, and then west again.  There are several little climbs, but nothing like what cyclists will face the next day in Stage 12.  The stage finishes in Toulouse, which is where Stage 12 commences.

What makes tomorrow's stage so interesting is that team strategies will, like they often do, dictate the pace of the race.  Will the stage be short enough that several riders will break away and try to get a stage win?  Will Stage 12's mountain climbs worry those competing for the general classification enough that they'll ride Stage 11 at a leisurely pace?  We certainly don't know the teams' strategies!  Our model has the stage at a fairly fast pace.

• Stage 12:  3h 39' 54" (prediction)

Stage 7 so crushed me that I'm worried that I'll be watching a stage and wondering why the cyclists aren't doing anything more than looking at the scenery.  And then thoughts of Stage 3 enter my mind, which makes me worried about watching a stage with my jaw agape at just how fast the riders are going.  I'll take the second scenario because I like watching fast racing.  The physics is easy.  Anticipating what teams choose to do is much more difficult.  I can't wait to see the Tour de France back in action tomorrow!

Wout van Aert Out-Sprints Everyone!

Despite not having help from teammates at the very end of today's stage, Belgian cyclist Wout van Aert just edged Italitan Elia Viviani for the win.  Viviani was denied his second win of this year's Tour de France as van Aert got a third win for Belgium.  Check out how close the finish was (click on image for a larger view).

That's van Aert in the yellow and black, just ahead of Viviani in blue.  Racing was very fast today, and I could tell halfway into the stage that our prediction would be a bit slow.  Several riders got caught behind the lead group of sprinters that emerged from the peloton.  Giulio Ciccone fell all the way from 2nd and only 23" behind to 10th place in the general classification,  02' 32" behind Julian Alaphilippe.  Thibaut Pinot went from 3rd and just 53" behind to 11th and 02' 33" behind.  Pinot will be among many cyclists who will be kicking themselves this evening.

We might want to kick ourselves for not upping our power a bit on a stage prior to a rest day.  Still, I wasn't expecting cycling to be quite so fast.

• Stage 10:  4h 49" 39" (actual), 5h 10' 40" (prediction), 21' 01" slow (7.26% error)

Look at van Aert's average speed.

• Stage 10:  12.52 m/s (45.05 kph or 28.00 mph)

That average speed was 2 kph faster than the fastest imagined by the race organizers.  I confess that predicting stage-winning times is much harder this year.  My students and I have enjoyed years with half the stages predicted to better than 3%.  This year, we've predicted half of the first 10 stages to better than 4.6%.  But we've really missed on a couple stages.  We had Stages 3 and 4 completely flipped, and we never imagined such a slow Stage 7, even after a grueling Stage 6.  The fact that predicting is getting more challenging motivates me to continuing learning.  Life as a scientist is never dull!

Cyclists will enjoy a rest day in Albi tomorrow.  Stage 11 will be pick up there on Tuesday.  I'll post our prediction for Stage 11 during tomorrow's rest day.

Impey Makes South Africa Proud!

South African cyclist Daryl Impey held off a furious challenge from Belgian Tiesj Benoot in the final sprint to the finish to take Stage 9.  It was a great stage to watch if you love attacks and pursuits, but not so much if you expected the famous sprinters to get out of the peloton and compete for the stage win.  The gap established by the leaders and pursuers was large enough that the peloton was happy to enjoy a leisurely ride to the stage end.  Check out Impey crossing the finish line (click on image for a larger view).

Our model did quite well today.  But as I noted in yesterday's post, I was rooting for the lead riders to sneak in under 4 hours.

• Stage 09:  4h 03' 12" (actual), 3h 56' 42" (prediction), 06' 30" fast (-2.67% error)

Given that the main sprinters were not a factor in the stage win, I'm more than happy with our error.  The peloton, including Julian Alaphilippe, came in more than 16 minutes later.  Alaphilippe keeps the yellow jersey for France on Bastille Day.  Some of the bigger sprinters, like Peter Sagan, came in more than 5 minutes after the peloton.  Check out Impey's average speed below.

• Stage 09:  11.68 m/s (42.06 kph or 26.14 mph)

It was a tad slower than our model predicted, but impressive nonetheless.

Tomorrow's 217.5-km (135.1-mi) Stage 10 is listed as flat, but with a category-4 climb and three category-3 climbs, it could very well have been classified as a light hilly stage.  The commune of Saint-Flour hosts the start of the stage, and then riders travel southwest to Albi.  They'll be making their way to the Pyrenees.  Our prediction is given below.

• Stage 10:  5h 10' 40" (prediction)

Cyclists will stay in Albi after the stage ends.  Tuesday will be the first rest day.  Will cyclists go all out, knowing that they'll be able to rest on the following day?  Will I be rooting for the lead cyclists to not sneak in under 5 hours?!?

An Inspiring Ride by Thomas De Gendt!

There is neither a rider nor a team that I'm rooting for in this year's Tour de France.  But there are stages like today's Stage 8 when it's impossible for me to stay neutral.  Thomas De Gendt was awe inspiring today.  The 32-year-old Belgian broke away early in the race.  He and Italian cyclist Alessandro De Marchi cooperated for much of the race, and when De Marchi nearly crashed and nearly took out De Gendt (click on image for a larger view),

cooperation continued after De Marchi caught up with De Gendt inside of 60 km (37 mi) left in the stage.  But on the final category-3 climb, De Marchi could no longer stay with De Gendt.  I caught the screen capture below when I saw De Gendt look back, perhaps thinking he was going to have to win it alone (click on image for a larger view).

I was then pulling hard for De Gendt to make it to the finish line without being caught.  And he didn't disappoint!  Check him out full of joy as he's won the stage (click on image for a larger view).

You can see Thibaut Pinot and Julian Alaphilippe, who came in second and third, respectively, in the background after they valiantly tried to catch De Gendt.  I was hoping De Gendt would sneak in under 5 hours, but I was nearly yelping with how good our prediction turn out.

• Stage 08:  5h 00' 17" (actual), 4h 55' 42" (prediction), 04' 35" fast (-1.53% error)

After yesterday's disastrous prediction, I would have been happy with 5% today.  But I'm thrilled our model performed much better than 5%.  Our model has had lots of ups and downs so far.  The yellow jersey has had some back and forth, too.  Alaphilippe wrested the yellow jersey from Giulio Ciccone, who now sits 23" behind Alaphilippe.  Pinot is 53" back in third place.  Can a French rider take the Tour de France for the first time since Bernard Hinault won in 1985?

Check out De Gendt's impressive average speed below.

• Stage 08:  11.10 m/s (39.96 kph or 24.83 mph)

Tomorrow's 170.5-km (105.9-mi) hilly stage picks up where today's stage ended, in Saint-Étienne.  Riders won't have to any more traveling today!  One category-1 climb and two category-3 climbs greet riders on their way to the commune of Brioude.  They will mostly go west, but a little south, too.  Our prediction is given below.

• Stage 09:  3h 56' 42" (prediction)

I'll probably do tomorrow what I did this morning, and that's hope a rider gets in under the closest hour mark.

It's Groenewegen by a Nose!

Dylan Groenewegen has definitely put his Stage-1 crash behind him.  He looked great on the final sprint, just edging ahead of Caleb Ewan.  Check out how close the finish was (click on image for a larger view).

That's Groenewegen on the right in yellow and black; Ewan is on the left in red and white.  Peter Sagan is in the middle; he came in third.

And now we come to our prediction.  I began watching the stage early this morning, hoping our prediction would be as good as yesterday's.  But then the racing turned out to be very pedestrian, sluggish, in fact.  Narrow roads squeezed the peloton in many places, but the riders simply looked content to take it easy on today's longest stage.  As the stage went on, I realized we were in for a terrible prediction today.

• Stage 07:  6h 02' 44" (actual), 5h 21' 48" (prediction), 40' 56" fast (-11.28% error)

This is, by far, our worst prediction of the race.  And it came after nearly being perfect yesterday!  Such are the vicissitudes of predicting the Tour de France.  Check out Groenewegen's average speed.

• Stage 07:  10.57 m/s (38.04 kph or 23.64 mph)

That's 2 kph slower than what race organizers thought would be the slowest average speed.  I'm sure fans on the sides of the roads were anxiously awaiting the peloton to come by, albeit later than they expected.  Did yesterday's grueling Stage 6 zap the riders' legs?  Most likely so.  We need to do better in the future anticipating such drop-off in performance after especially difficult stages.

Tomorrow's Stage 8 commences in Mâcon and takes riders 200 km (124 mi) south to Saint-Étienne.  The hilly stage has two category-3 climbs and five category-2 climbs.  Our prediction is given below.

• Stage 08:  4h 55' 42" (prediction)

We have the correct physics in our model, but we need to do better anticipating strategies.  We nailed it yesterday, but then botched it today.  What will tomorrow bring?