How it works is that if a player has played more than 75 innings, or bowled more than 75 innings worth of balls (75x60), his stats are left alone.
If it's less than 75 but greater than 50, his stats are nerfed towards mediocrity for someone of their type by 25%.
If it's less than 50 but greater than 25, same applies but 50%. Glenn Turner, for example, who played 34 matches, loses 50% of his extra average over a mediocre player. His average was 47, a mediocre top order player is 30, so Turner averages halfway between 30 and 47 in the simulator, i.e. 38.50.
If it's less than 25, same applies but 75%. In the ATG scenarios this doesn't matter but this is what we did for the 2015 CWC squads.
So Fleming is in the simulator as essentially a non-bowler (EconRate 7.0, BowlSR 100.0). His BowlSr of 29 is therefore nerfed 75% towards mediocrity for a non-bowler, giving an SR of 80 or so.