The spreadsheet also has data on outcomes. How hard the ball was hit.
So I suggested a couple things:
1) Use all of this to generate a measure of when a pitcher is losing it.
2) I thought also it would be useful to look at consistency by inning (variance) of the different measures.
3) Look at whether the pitcher is able to step it up depending on the situation (runner in scoring position) or facing the other team's best hitter.
The data is basically for one game, both starting pitchers.
That is a very limited amount of data, but if it is detailed enough he could still do some interesting things. However, just having 1 game of data isn't enough to say "Syndergaard can only throw 90 pitches". It definitely isn't enough data to say "guys get hit hard after 22 batters" because there were only ~40 batters in the entire game.
I'm 100% positive the kid will be evaluated on the process he develops, not the actual results. Your idea for generating a stat to tell when a pitcher is tiring is excellent, but don't base it on outcomes because those are highly variable events. Make sure he can explain what that means, and why 1 game of data is too small of a sample to draw general rules from.
Base the measure on aspects of the individual pitches like velo and spin rate. If arm slot data is present, look for a guy losing consistency in his arm slot. If location data is available, look for guys getting wild (the data should be represented as distance from the center of the zone, so also look for the pitches missing over the middle of the plate, not just off the plate). Things like that.
I would be willing to bet the data given to him was chosen precisely because there is a nugget of info in there that proves something the Mets believe in from an overall philosophy standpoint. One or both pitchers will have demonstrated a decline in velo, spin, location, arm slot, or something else the Mets key on, making this particular set of data a good "example" in their eyes. I wouldn't be surprised if this particular data set showed the Mets handled the pitcher "correctly", while the other team didn't.