Wimbledon 2018: Early Round Upsets Turn Betting Sheet Upside Down

• Almost all the top women lost in the first rounds at Wimbledon
• What does that mean for Simona Halep and Serena Williams?
• What does that mean for bettors?

For the first time in the open era, six of the top eight seeds in the Wimbledon women’s draw will not advance to the third round. Behold the following carnage:

• Garbine Muguruza, the defending champion and No. 3 seed, was knocked out in a sunset match 5-7, 6-2, 6-1 by Alison van Uytvanck.
• Caroline Wozniacki lost 6-4, 1-6, 7-5 to Ekaterina Makarova in the second round.
• Petra Kvitova lost 6-4, 4-6, 6-0 to Aliaksandra Sasnovich in the first round.
• Caroline Garcia lost 7-6(2), 6-3) to Belinda Bencic in the first round.
• Sloane Stephens lost 6-1, 6-3 to Donna Vekić in the first round.
• Elina Svitolina lot 7-6(3), 4-6, 6-1 to Tatjana Maria in the first round.

While I was writing this, Karolina Pliskova was down a set and a break to Michaela Buzarnescu, and I was worried I was going to have to add another tombstone to this graveyard.

What these upsets mean for bettors

Before the tournament, some of these players carried pretty strong odds to win Wimbledon 2018. Petra Kvitova was +600, which carries quite a lot of implied probability. If you add up the implied probabilities of these six players, you get something just over 43%. Wiping all that out means the sportsbook has to get shorter on the top players left in the tournament.

The top two players have thus absorbed an extra 30% in implied probability, with the rest scattered amongst the field. The sportsbooks are trying to fix their lines by leaning even more heavily on the remaining favorites, which might seem like a risky strategy.

The sportsbooks are obviously thinking on an individual level, not taking a broader view. Their thinking is that with all these top players out early, Serena Williams’ path to her eighth Wimbledon title looks a lot easier.

A contrarian might say that all these early exits show that the difference in skill between top women’s players and the field is narrower than we thought, and that taking a flyer on a longshot player is the move here.

A logician might barge in on that contrarian and say that’s a fallacy of division argument, and that the failure of other top players can’t say anything about Serena Williams’ or Simona Halep’s prospects.

However you want to think about it, a lot of top players are out early in the women’s draw and the odds on the remaining favorites are shortening to make up the slack. The improvement in odds for Serena Williams and Simona Halep is not based on anything they’ve done so far at Wimbledon, beyond survive the early rounds.