according to wikipedia,

Kelly bet is: f* =(bp-q)/b
where

f* is the fraction of the current bankroll to wager;

b is the net odds received on the wager (i.e. if the odds are 2-to-1 ("even money") then the value of b is 1) ;

p is the probability of winning;

q is the probability of losing, which is 1 − p.

but, some people say,
optimal bet = bankroll x EV/Var

which is correct?