Why did NHL ban 00?

Why the NHL Banned the Number 00

It sounds like a joke, but the truth is surprisingly technical: the NHL banned the numbers 0 and 00 not for superstition or tradition, but because of old-school data limitations. Back in the 1990s, the league’s player database systems couldn’t properly process "null" values—something that might make any modern programmer wince.

Only one player ever wore a single 0 in NHL history: defenseman Neil Sheehy, who donned the number during the 1987–88 season with the Hartford Whalers. It was a rare sight, and it wouldn’t happen again—at least not officially. When the league began centralizing and digitizing player records, the presence of "0" and "00" confused the system. In programming terms, zero can be interpreted as "no value" or "null," causing glitches in databases that expect actual identifiers.

To avoid technical hiccups, the NHL simply outlawed both numbers. Since then, players have been limited to numbers 1 through 99, a rule that still stands today. While some minor leagues and international teams allow 0 or 00, the NHL has held firm—partly due to legacy systems, and partly because changing the standard now would create more complications than it’s worth.

So, no conspiracy, no superstition—just a quirky collision between sports and early computing. The next time you see a player pick their jersey number, remember: behind the scenes, it’s not just about style or sentiment. Sometimes, it’s about code.