A player's performance on a map is given in terms of score after a successful completion of the map.
Most of the time, combo plays a major part in the scoring system since it serves as a multiplier of the score.
Before ScoreV2, each game modes has their own scoring system in place:
While the issue only arise on very long and combo-intensive beatmap, if the player managed to exceed a combo of ~6,500 onwards, the player's score will begin to count backwards.
This is a known flaw with the 32-bit signed integer where (in computing) the max integer is 2,147,483,647.
This is where ScoreV2 comes in.
ScoreV2 attempts to standardise all the game modes' scoring system to 1,000,000 (1 million) score at 1.00x score modifier with extra score gains from spinner's bonus for osu!, drumrolls for osu!taiko, and bananas as usual for osu!catch.
Each of the hit objects are now part of the 1 million score and scaled accordingly rather than their own scoring values and bonus formulae.
ScoreV2 can be tested in Multi mode as one of the Match Setup's Win Condition.
As of 22 February 2017 (2017-02-22), the ScoreV2 system can be tested in Solo mode using the UNRANKED ScoreV2 game modifier.