It means designated hitter in baseball, the DH hits for the pitcher in the American league
The position "p" is for pitcher.
Middle Relief Pitcher. A pitcher who goes in around the 5th - 7th inning.
It's the walks and hits per inning pitched. In other words it's the average number of walk and hits a pitcher gives up per inning pitched.
This probably means that if he gave up, say, 5 hits over 6 innings, maybe 1 in each of the first 5 innings. In other words, he didn't give up all 5 hits to 5 consecutive batters.
SO means strikeouts.
WHIP stands for Walks plus Hits per Inning Pitched and is a relatively new statistic for pitchers. Add the number of walks a pitcher allows to the number of hits a pitcher allows and divide by the number of innings pitched. This gives you the pitcher's WHIP. Like ERA, the lower the WHIP the better. Example: A pitcher has pitched 100 innings, given up 30 walks and 90 hits. Add the number of walks allowed to the number of hits allowed (30 + 90 = 120) and divide by the number of innings pitched (120 / 100 = 1.2). The pitcher's WHIP is 1.2.
There is no such thing as an ace in softball; you might be thinking of volleyball or tennis.
Complete Game. When a pitcher starts and finishes the same game.
'IN' stands for 'innings' and is usually seen in a line of statistics for a pitcher.
Extra base hits
It can either stand for Wild Pitch or Winning Pitcher.