Starting in the 1990s, a walk-off grand slam that erases a three-run deficit has come to be known as an ultimate grand slam. There have been 29 such instances documented in major league history – all taking place during the regular season, 15 of those coming with two outs. Of the 29 home runs, only Roberto Clemente's was hit inside the park, at spacious Forbes Field on July 25, 1956. Pirates manager/third base coach Bobby Bragan instructed him to stop at third, but Clemente ran through the stop sign to score the winning run. Alan Trammell's June 21, 1988 and Chris Hoiles' May 17, 1996 grand slams occurred under the most dire situation: bases loaded, two outs, full count, bottom of the ninth inning, and down by three runs.