I've been playing recreational softball and tracking my players' on base percentages for about 20 years. If you were going to pick what a 'good' player is based only on that number, I would say you need to bat .850 or better to be one of the players I would consider in the top tier. read more
For slow pitch I would consider a .550+ batting average to be great (the other 45% of the time you got out you still could have hit the ball hard though), .450+ to be decent/OK, .350+ to be mediocre, and anything lower to be bad. read more