(50 BTC - 1 BTC fee) * (score) / (total score)
This.
Btw, the explanation on your site does not reflect the current scoring system.
I know that, unfortunately it's pretty complex stuff to explain (exponential functio, reason for making older shares less valuable, renormalization) and I failed with some easy description for 'common users'. But because expected payout is +- the same as for share based calculation (without pool hoping), I feel like shares/total shares * 49 is correct enough for average user.