1. Pitch type and result, by count
Record what was thrown and what happened: ball, called strike, swinging strike, foul, in play. Sorted by count, this shows what the pitcher reaches for when he's behind and when he's ahead, and what hitters do with it. A pitcher who throws 70 percent fastballs on 2-0 is predictable, and the other dugout figures it out before you do if you aren't counting.
2. Location, not just the result
Tap where the pitch crossed. A called strike on the black and a called strike down the middle are both strikes in the book and very different pitches. Location over a game shows whether he's commanding or getting away with it, and where his misses cluster when he tires.
3. Batter hand
Left or right, for every pitch. By the fifth inning you can see whether his changeup is working against lefties or getting hit, and that's the pitch-calling information that matters most with the game on the line.
4. The count against the limit, before the inning starts
Know before you send him out whether he has 12 pitches left or 30. The decision to let him face one more hitter should be made with the number in front of you, not reconstructed from memory.
5. His tendencies over the season, not just today
Today's game is a small sample. Over 15 games the pattern is clear: what he throws in each count, which pitch gets swings and misses, and where he lives when he's ahead. That's the scouting report the other team would write about him. You should have it first.
What you don't need to track
Opposing batters by name, exit velocity, spray charts, defensive positioning. Those are scorekeeping for the people in the stands. The dugout needs the pitcher's data, recorded fast enough that the coach can still watch the game.
Afterward
The game's pitches should join the pitcher's bullpens in one record, so rest days and readiness are computed from everything he threw this week, not just the game.