40% batting average means what ? Does it mean that out of 100 trades, 40 are winning trades and 60 are losing trades ? If yes, plain math may be misleading by terminological jungle.
Suppose you had Rs. 1 lakh to start with, and entered a series of trades with the full capital, and had 60 consecutive losing trades, and then 40 consecutive winning trades, the math would be totally screwed up. The bottom line after each trade would decide the percentage of profit/loss for each trade.