Carlos Alcaraz won the first set he ever played at the ATP Finals, but he lost the match so what needs to happen if he wants to qualify for the semi-final?
The first match Alcaraz ever played at the ATP Finals was against Alexander Zverev. It was a tricky match that was ultimately won by Zverev, who benefitted from the conditions. The event plays fast, so fast that it's one of the fastest events in years.
Multiple players spoke about it, including Alcaraz, who wondered about it after the match. It certainly hurt in the match because he couldn't quite deal with the serve well enough to give Zverev many problems in return.
The loss puts him in a tough spot because he needs to be really good in the next two matches to have a chance to qualify. So what needs to happen for him to find himself among the last four standing?
Well, winning both matches would be a good start and would give him the highest chance of qualifying. His next match will be against Andrey Rublev, and after that, he will face Daniil Medvedev.
He can obviously win both matches, but it won't be easy, especially against Medvedev who beat him the last time they played. Rublev is excellent indoors, so that's going to be complicated as well.
If he loses to Rublev in the next match, then he needs things to go a certain way. He'll need Zverev to beat both Rublev and Medvedev, and he himself will need to beat Medvedev in the final match, creating a situation where Medvedev, Rublev, and himself all have one win.
In that scenario, the German with three wins would obviously advance, and he would be followed by the player with the best set % win record. That is the ratio between sets won and sets lost.
For example, a 5-3 record is worse than a 5-2 record, as the percentage is better in the latter (71%>62%). Because of that, Alcaraz's set won against Zverev really helps him, and he would ideally need to win at least one set also against Rublev if he was to lose, and also beat Medvedev in two sets. That would almost certainly guarantee him a semifinal spot.