Ok, I know it's a small sample size, not even five full games and 275 minutes of hockey. Even still, Michael Leighton's 0.87 goals against average is ridiculously impressive. Since replacing the injured Brian Boucher halfway through game five of the Boston series he has stopped 124 of 128 shots against for a save percentage of .969, crazy.
As it stands currently, Leighton is hanging with the greats of alltime. Only seven times in NHL history has a goaltender kept his GAA under 1.00 for an entire post season, all 1952 or earlier. Alex Connell of the 1927 Ottawa Senators had a 0.60 average in six games and Boston's Tiny Thompson had the same average over five games in 1929. In 1952, Terry Sawchuk had the greatest goaltender performance in NHL history in leading Detroit to the Cup. He won all 8 games, collecting 4 shutouts and allowing only 5 goals for a 0.62 GAA.
In all likelihood, Leighton will not win his next six games while allowing less than a goal per game. However, his current hot streak is not unprecedented in his pro career. Over 19 playoff games in his American Hockey League days, he a collective GAA of 1.35 and Save Pct of .956. In fact over his last two AHL post-seasons consisting of 11 games, his average is exactly 1.00 with an amazing Save Pct of .970, maybe Leighton will go undefeated the rest of the way after all.