Additive Time Tennis
Additional Time Tennis also known as ATT or Growing Tennis is a blanket term for tennis variants that involve the additive change of duration, rather than the multiplicative as seen in Multiplied Time Tennis.
Layout
For additional time tennis, rounds usually start at a very low number. From there, every round after will be a fixed amount of time longer; usually a second.
For subtraction, you start at a higher number and go down. This puts a limit on how many rounds are possible, whilst ATT can go on forever.
Notable Matches
The Self Tennis Collab by nonojuju uses this format for each match.