posted 1/4/11 : Event ends when fifty percent of the field has been busted out
Online poker giant Pokerstars has launched a new tournament concept after some months in development and testing.  The newly introduced Fifty50 Sit and Go is a type of one-table event which ends when half of the entrants have been eliminated.
For example, in a 10-player Fifty50 tournament, 5 will be paid.  Half of the prize pool will be distributed equally among the 5 winners, and the other half will be distributed among those same 5 players based on the chip count percentages at the end of the event.
"The 6th-10th place finishers who have been eliminated win nothing," Pokerstars clarified this week. "So in a 10-player $10+$1 Fifty50, the prize pool is $100. Each of the final 5 finishers would receive $10 each, plus a percentage of the remaining $50 in the prize pool. As a more detailed example, in a $300+$17 tournament with ten entrants, the total prize pool is $3,000.  Each player starts with 1,500 chips.
To calculate the value of Player 1’s chips, multiply half the prize pool ($1500) by Player 1’s portion of the total chips in play (4300/15000), a total of $430. Adding the returned buy-in awarded to each player who cashes results in Player 1’s total prize amount of $730 ($430+$300). As a formula, an individual’s payout would be expressed as:
payout = buy-in + (ending chip count) x (0.5 x total prize pool)
(total chips in play)
The Fifty50 tournament lobby displays the approximate amount per 100 chips to be paid out when the tournament ends. The value displayed in the Fifty50 tournament lobby is rounded down to the nearest cent, but payouts are calculated so that the entire prize pool is paid out.
Due to the unique payout structure, Fifty50 tournaments are not eligible for any Tournament Leader Board points.”