People in sabermetrics circles have been decrying the tactic of bunting to advance runners for a long time. The argument goes that moving a runner from first with zero or one out to second with one or two outs often actually lowers the expectation of scoring and also winning the game. In a time when almost any major league hitter can hit a home run and games regularly feature five or more runs by each team, it's hard to argue against playing for more than one run. It wasn't always that way, however. In the early part of the twentieth century, sacrifice hits were extremely important. In games that often ended 3-2 or 2-1, every run was vitally important. The all-time leader in sacrifice hits, Hall of Fame second baseman Eddie Collins, played from 1906-1930 and topped 30 sacrifice hits six times. For comparison's sake, no one in the major leagues last season had more than five sacrifices.
Collins was by no means the most prodigious bunter of his day, however. Much like Hank Aaron, his record was not achieved by leading the league year after year, but rather through longevity. Collins never led the league in sacrifice hits but played for twenty-five years. Despite his long playing career, if not for an unfortunate pitch from Carl Mays it's possible Collins wouldn't hold the sacrifice hits record.
On August 16, 1920, the Cleveland Indians came to the Polo Grounds in New York to square off against the Yankees. Mired in a tight, three-way pennant race (for a visual display, see this cool site) along with the Chicago White Sox, the third-place Yankees saw the late-season series against the Indians as a crucial time to make up ground. Taking the mound for the New York club was ace Carl Mays who would end up with 26 wins for the season. Unfortunately, the game became known for much more than being a contest between two good teams. During the game, a pitch from Mays hit Cleveland shortstop Ray Chapman in the head. Chapman lost consciousness soon after and died following emergency operations to remove pieces of his skull in an attempt to relieve pressure caused by brain swelling. As the New York Times reported,
The shock of the blow had lacerated the brain not only on the left side of the head where the ball struck but also on the right side where the shock of the blow had forced the brain against the skull, Dr. Merrigan said."
Though Mays protested the beaning wasn't intentional, many figured his prior reputation as a head-hunter meant hitting Chapman in the head was a planned incident. Whatever the case, Mays thereafter had to deal with harassment from the stands. Though his claims aren't necessarily backed up by his overall numbers (only 207 wins, to point out one example), Mays often claimed the fatal beaning was used to keep him out of the Hall of Fame. For much more on both the beaning and the whole baseball landscape in 1920, I suggest you read The Pitch That Killed by Mike Sowell.
The reason I bring up this unpleasant time in baseball history is because of the victim. Chapman was 29 when he died, with any number of years left to play in his career. He still has three of the top fifteen single-season marks for sacrifice hits, including the single-season record with an amazing 67 sac bunts in 1917. Though his playing career was so suddenly ended, he is now sixth on the list of most career sacrifice hits with 334. Though it's obviously hard to figure how the end of the deadball era after 1920 would have changed his numbers, it's not hard to see another few years in the league placing Chapman at the top of the career list. Five more years of his by then usual 40+ SH per year would have put him comfortably above Collins' eventual career mark of 512.
It's extremely unlikely anyone will ever again challenge Collins' mark or even Chapman's. The active career sacrifice hits leader, Giants shortstop Omar Vizquel, has 233 bunts. He's forty-one years old and still over one hundred bunts behind Chapman. Only six active players total, none less than 38, have more than one hundred career sacrifice hits. It just is another example of how some records are unbreakable, not because of a lack of skill on the part of others, but rather because of the changing strategy in the game.