1) Clutch probably doesn’t exist – or at least there is not a lot of evidence that it exists. It is being studied (there is a clutch score on fangraphs that I think refers to exactly what you were asking – how often they performed during high leverage situations) but it has not been studied in depth and may easily be noise. At the same time, there may be a combination of it existing and not existing. For example, maybe it is impossible for a player to “up their game” in clutch situations, but it is possible for a player to “choke” from nervousness (thus making unclutch possible, while truly being clutch is impossible).

2) In a way, that is tracked by WPA. A player who is constantly not succeeding in high leverage (“clutch”) situations is going to have a much lower WPA than their hitting stats suggest they should simply because WPA penalizes a lot for not succeeding in clutch situations.

It is worth mentioning that WPA assumes that all teams and players are equal in talent, which we know they are not. As you mentioned, a guy who was able to hit a single with Griffey on second is much less likely to get the runner in than a guy who hits a single with Ichiro on second, and in some ways WPA penalizes the batter for not being able to get Griffey home even though it was due to Griffey simply being slow as shit. These are things that are problems with these stats, but mostly due to the novelty of the stats and how much resources people have to study and perfect them. Someday it is likely that there will be a WPA that takes into account far more variables than it does now.

If I remember the book was about Texas football – college style, but I think it could be applied to any sport. In any case, I’m thinking I like watching the M’s.

This is debatable though. This is not like a college player who may never succeed in sports and needs to also get an education in order to make a modest wage. These are people played millions and millions of dollars on an unbreakable contract. They are bought, traded and sold like rare art because they are valued like rare art and in some ways perform the same function.

No one wishes injury on anyone, especially serious injury – but when it is in two people’s mutual interest to keep playing – Beltre to hopefully earn a large contract in the offseason and the Mariners to get the performance they are legally required to pay him for – then he is a resource that can be tapped for the Mariner’s benefit.

Also, the risk of injury is inherent in all sports. In some sports, that does not justify risking further injury, I agree. But in baseball, they have unbreakable contracts SPECIFICALLY for that reason – so that you are forced to keep paying the player because they are going out there and risking injury at your expense. What you are requesting gives justification for non-guaranteed contracts, which I can promise you would make the players that are risking injury far less happy.