Rob Minto

Sport, data, ideas

Tag: Novak Djokovic

Murray vs Djokovic charted: a streaky final

In all the excitement and euphoria of Andy Murray’s Wimbledon victory – in the UK, at least – one thing has hardly been mentioned: how strange a match it was.

For a 3-setter without any tiebreaks, it was as close and as tight as possible. But yet it didn’t follow the usual pattern of tight games, with each player holding serve until one blinks or a tiebreak ensues.

Instead of the “I hold, you hold” rhythm of most matches, the final instead went in hot streaks. Murray just got more of them than Djokovic.

In fact, looking at the chart below which shows the games won in the match as a descending ladder, there was only one brief period of the game (at the end of the first and start of the second sets) where both men held serve regularly.

You can see that Murray only won two games in isolation (ie sandwiched by Djokovic games). During the rest of the match, he won games in streaks of 2, 3, 3, 5 and 4.

Perhaps it was the heat, or the occasion. Whatever, it’s certainly history.

Why Nadal-Djokovic may be the best tennis rivalry ever

French Open final, 2012

Tennis thrives on great rivalries – they are almost more famous than the players themselves. Borg-McEnroe, Sampras-Agassi, Federer-Nadal.

But the current rivalry between Novak Djokovic and Rafael Nadal may be the best ever. Here’s the killer fact why:

They are the only pair (in the men’s game) to have contested each of the four major finals. No-one else has done that – not any of the rivalries I mentioned at the start, nor even any of the pre-open era rivalries such as Laver-Emerson.

Why is that important? Well, it shows that they are both hugely talented on all surfaces, and have stamina to get to many major finals. And although this Friday’s meeting at the French Open is a semi rather than a final, due to Nadal’s ranking slipping after a long injury, who would bet against them overtaking the record of eight slam finals held by Federer-Nadal?

Which makes you realise how many finals Nadal has played against Federer and Djokovic – only three of his 16 major finals have been against other players (Soderling, Berdych and Puerta, winning them all).

The BBC (wrongly) stated that: “The Monte Carlo final [earlier this year] was the pair’s 34th meeting, making their rivalry the most prolific in the modern game, with Nadal leading 19-15 overall and 12-3 on clay.”

Update: the BBC updated the story, thanks to Piers Newbery.

Not quite. Lendl and McEnroe played 36 times. But that’s just another milestone soon to be passed by Nadal-Djokovic. Only injury can prevent them breaking several more records.

Djokovic vs Federer vs chance: is the draw fixed?

On Friday, Roger Federer and Novak Djokovic line up in the semi-final at Wimbledon. Although they have never played each other on grass before, a semi-final meeting has a very familiar ring to it.

Well, that’s because it is familiar – and a bit too frequent, when you look at the odds.

In fact, since Djokovic broke into the top 4, it is amazing how many times he and Federer have been placed in the same half of the draw. For those unfamiliar with how it should work, here it is:

  • The number 1 and 2 seeds are placed at opposite ends of the draw. Then, the 3rd and 4th seeds are picked at random and placed in one half or the other, away from the top 2 seeds so that they can only meet at the semi-final stage.
  • For many years, Federer was #1 in the world, with Nadal #2 and Djokovic #3 or #4. Now, Djokovic is #1, with Federer #3. Never in a slam have Federer and Djokovic been 1 and 2 seeds.

So, to recap: for since half way through 2007, for each of the four slams in a year, it has been a 50:50 chance that Federer and Djokovic should end up in the same half of the draw.

In fact, since Djokovic has broken into the top 4, (which has coincided with an ever-present Federer in the top 3), they have been in the same half of a grand slam draw 16 times out of 21.

To get 16 heads flipping a coin 21 times is not good odds. For what should be a 50 per cent chance, it is running at over 76 per cent. That looks suspicious.

And in 2009 and 2011, they were in the same half for EVERY slam. That’s a 1 in 16 chance for the year, repeated.

Overall, unless my statistics is letting me down, the chance of 16 out of 21 coin tosses coming up heads is 0.0097 – that’s the binomial probability. Here’s the calculator I used – enter 0.5, 21 and 16 to see the results. That’s not very likely.

[Aside: They are such good players, that out of the 16 times they have been in the top 4 seedings and drawn in the same half, they have managed to get to play each other 9 times, with one or both players going out before the semi stage 7 times.]

Why would you want to play Federer and Djokovic in the same half? To get Nadal in the final, that would be one possibility, to try and engineer more Nadal-Federer finals. Or, more likely, it’s just chance. But a few more Federer-Djokovic semis, and perhaps the players should be hiring statisticians as well as dieticians.

Here’s the data in a Google spreadsheet.

The limits of sports stats: the example of Nadal and the WSJ

This year in tennis is been all Djokovic and that winning streak. The narrative of sports is always about who is “the Man”, so therefore, Rafael Nadal must be a spent force.

The Wall St Journal have, they think, proved it. In their piece Nadal Looks Surprisingly Human in Paris they look at the stats of Nadal’s first four matches this year, and compare to the years he has won before.

Nadal’s stats don’t reflect a full-blown disaster. But compared to his first four victories in the years he won here, Nadal is spending on average a half hour longer on court and breaking opponents’ serves far less often. All this despite not playing a single seeded opponent so far.

What’s wrong with this? First off, players who are seeded CAN’T meet another seed until the third round anyway, so that’s hardly stunning. Let’s look a bit more at the stats they cite.

2011 85.5% 39.7% 62.8% 85.7% 2:52
2010 85.2% 50.9% 68.2% 100% 2:18
2008 87.8% 65.2% 76.8% 100% 2:05
2007 86.8% 50.9% 68.9% 100% 2:14
2006 81.8% 43.9% 62.9% 85.7% 3:04
2005 87.7% 44.6% 66.4% 92.3% 2:09

Sources: ATP World Tour, Stats Inc.

His average match length is high, but it was higher in 2006 when he won the title – hardly shocking. The only 2011 stat quoted which is worst in the list is the percentage of return games won – 4 per cent lower than the next lowest. Four per cent, which works out at about 2.5 games on the opponent’s serve that he hasn’t won in 4 rounds – less than a break of serve less per match.

So we have boiled Nadal’s struggle down to about a break less per match from 2006, perhaps two per match from his peak, plus a bit more time on court.

It’s hardly evidence of decline. But stats are like that. They don’t always show what seems evident to watchers and commentators. They don’t show the workrate, the struggle on points, the extra deuces, the attitude. Perhaps those things are there, perhaps we’re seeing what we want to see to fit the narrative. Let’s see what happens from here to the final.

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