DH- designated hitter, AL teams use a DH in their lineup instead of having the pitcher hit.
AL- American League
NL- National League
WAR- Wins above replacement, how many more wins a player is worth compared to a league average “replacement” player
WHIP- Walks hits per inning pitched
BB- Base on balls, walk
SB- Stolen Base
Ace- Teams best pitcher, typically first in the rotation
Cleanup Hitter- #4 in the batting order, usually teams best hitter or one of them.
ERA- Earned Run Average, the average number of earned runs a pitcher allows.
RBI- Run batted in, when a hit, sac fly, etc. lets to a run or more being scored.
Run- When a run is scored.
Double Play- getting two outs at once.
Error- When someone makes a mistake, typically a missed groundball or overthrow.
Single- a hit lending with batter on 1b
Double- a hit ending with the batter on 2b
Triple- a hit ending with batter on 3b
HR- typically when a ball is hit over the fence, batter gets to come home. Very good.