How this calculator works: WCVL baseball uses the player's age on September 1 immediately before the playing year. The WCVL playing season automatically rolls to the following year each September 1. WCVL adds a local 5U division for players age 4–5. Players then advance through 6U, 8U, 10U and 12U. A player may play in an older division when league rules allow, but may not play down into a younger division for which the player is not age eligible.