Here's an idea I've pitched before less the crediting system: Lower the flag HP to very low levels (previously had been implemented as one-strike ownership), provide respawn location advantage to the defending guild, have a countdown timer that resets whenever a new guild takes the flag, and provide, upon the countdown timer reaching zero, a victory credited to the guild members that held the flag at that time, with the total number of guild victories a player has participated in displayed in their user profile. A participating guild member can subsequently redeem their victory credits for prizes.