A Short Explainer on Getting to a Laver Cup Decider

In the third instalment of the Laver Cup, Team World came the closest it has ever come to defeating the juggernaut that Team Europe continues to be. With a Day 2 score of 5-7, World, in taking the first two matches, made the contest as close as it could have been. There was some confusion about that fact by the TV commentators who seemed to think that it was still possible for the teams to get to a 13th match. Here I explain why that wasn’t the case and what would have had to happen to reach a decider.

Laver Cup history isn’t long. This makes it a bit silly to talk about trends. But throwing some statistical caution to the wind, it does seem interesting that World has bettered or equalled itself by the end of Day 2 with each year of the event.

The 11 points Team World earned in Geneva is its best result yet. Short of winning the event, it could only outdo itself by getting to 12 at the end of Day 3 and forcing a match decider, something that has yet to happen at Laver Cup.

Some of the commentators covering the event seemed to think a decider could always be forced. It wouldn’t be the first numerical blunder made on a tennis broadcast but one would think could have been avoided by adding multiples of 3 to Team World’s Day 2 score.

Readers of this blog won’t have any trouble realizing that there are only a handful of Day 2 scores that can allow both teams to get to 12-12 after the 12th match of the final day. Those are:

  • 0-12
  • 3-9
  • 6-6
  • 9-3
  • 12-0

Less obvious is how likely each of these were this year. Considering the hardcourt player ratings of each singles and doubles pairings on Day 1 and Day 2, the chart below shows each score Team World could have had after Day 2 and the expected chance of each.

Overall there was just a 1 in 3 chance that Team World could have ended up with one of the 5 scores that could allow a decider. The most probable of those being a score of 3-9, World being the underdog in all of the singles matches but favored in all of the doubles. It is interesting to see that the score they actually achieved was, at 17%, just slightly less likely than the 3-9 they could have ended up with. And it had to be one of the bigger surprises of the event that Jack Sock got his first Laver Cup singles win to help World get there.

Expected chance of each Team World point score going into Day 3 of the 2019 Laver Cup. These percentages are based on 50,000 simulations of outcomes of the actual Day 1 and Day 2 lineups.

When Team World will get its next chance at the 2020 Laver Cup in Boston, I’ll be watching to see if it can surpass its personal best of 5 after Day 2 and 11 after Day 3.

And I hope I am around when one of the teams comes back from a 0-12 deficit to force a decider in Day 3. With the lineups this year, there were just 6 of 50,000 event simulations where that happened. So we may all have some time to wait for that one. Seeing the first decider, on the other hand, might be just a year away.