Which American is credited with introducing tennis's tiebreaker system?

Jimmy Van Alen is credited with introducing tennis’s tiebreaker system. The American player, official, and tennis promoter developed the Van Alen Streamlined Scoring System, or VASSS, to prevent long sets and matches from continuing indefinitely.

Van Alen’s tiebreaker was unveiled experimentally in 1965 at the Newport Casino tournament in Rhode Island. His original preferred format was a sudden-death, best-of-nine-points tiebreaker: the first player to reach five points won, even without a two-point margin.

The US Open became the first Grand Slam tournament to use a tiebreaker, introducing Van Alen’s nine-point version in 1970. The familiar best-of-12-point format, won by reaching seven points with a two-point lead, emerged later; the US Open adopted it in 1975.

A common mix-up is crediting the first tournament or governing body that adopted the rule rather than its principal advocate. The 1969 Wimbledon marathon between Pancho Gonzales and Charlie Pasarell helped build support for tiebreakers, but Van Alen is the canonical answer to who introduced the system.