Now imagine this: In the distant future, let's say ten years from now, you have managed to get the job as a coach for one of the world's top tennis players. The ATP final is here, and your man will pass the group stage if he just serves out the match, leading 5-4 in the third. However, his group is extremely tight. Who advances depends on the game count with this single decisive game making all the difference (it is a three-way race with three players about to get two wins and the same win-loss ratio in the set count). If your player gets broken, he won't pass the group stage due to the game count, no matter if he wins 7-5* later on. To make matters even more thrilling, reaching the semi will likely suffice to give your player the year-end number-one spot. In your contract, there is a huge bonus if your man pulls that off. When your player steps up to the service line and bounces the ball, you can hear your heart beating.

And here is the tricky part - in our imagined scenario - the player you are coaching is one out of two possible options:

Either you train Brilliant Choker (his name is just a funny coincidence due to the parents not speaking English), perhaps the best player in the world, but with an unfortunate habit of getting tight when closing out matches. His chances of winning the points on serve are 80 % in this particular match-up. However, from painful experience, you know that his level drops dramatically if he gets a match-point. Whenever he has a match-point, his probability of winning the point on serve is just 40 %. Curiously enough, he can still play good in other tight situations, for example, deuce or break point down. Thus for all other situations, except having match-point, the 80 % win probability applies.

The other option is that you train another player, namely Nerve van Steel. He is also a good candidate for the world's best player. Recall that from our starting assumption, the top spot was on the line. However, unlike Brillant Choker, your man van Steel is a miracle of composure in this case. The win percentage on serve is the same independent of the score and is given by 70 %.

So who would you rather coach in such a situation? Both players are dominant on serve and have a good probability of succeeding, obviously. Thus your chances of getting the bonus are promising, no doubt, but who would you give the best odds? The math nerds can compute the probabilities, most likely, but it takes a little work (particularly the case of Brilliant Choker requires a bit of patience). The experienced betters might have a feeling for the right answer and could make a good guess without actually making the computation. Others could make a choice in the poll, depending on who you sympathize with. Federer fans that have been burned by this year's Wimbledon will probably refrain from voting. Note though, that this thread is not intended as a dig at the old man - and who knows, Brilliant Choker might be the guy with the best chance after all.

A bonus point is awarded to anyone that can give the correct probabilities for "Nerve van Steel" and "Brilliant Choker" to serve out the match for the given specifications.

* For this to make sense, actually 7-5 has to give an identical game count in the three-way split (6-4 gives a better ratio), and we assume that things come down to counting points, which is not beneficial for our hero.