Splatoon adjusts Tower Control in today's Free 2.2.0 update

Today's Splatoon update includes changes made to all class weapons, adjustments to various stages, new matchmaking for S-rank players, and rule adjustments Tower Control mode.

Rapid Blaster Pro

Tower Control players will observe that the Special Gauge will charge gradually for whoever controls the Tower, regardless of which team is leading. If neither team has the Rainmaker, the Special Gauge will charge for the losing team, though the rate at which it increases automatically has been slowed.

Here's a link to a pdf with the full spec of the update - http://splatoon.nintendo.com/assets/media/splatoon-patch-v2-2-0-notes.pdf