I've been giving it some thought as to the hockey books I've read in regards to "new" stats being introduced.
The early hockey almanacs didn't always have GP listed for skaters. This almanac that I've read from 1974 omits that from players in the up until the 1930s. Then, assists weren't "recorded" from the first NHL season (1917-1918) in an almanac I have from 2000. Go figure that in Total Hockey (c2005) they have the assists from (1917-1918), even though it mentioned in the 2000 almanac that they weren't recorded in the first season (I thought that meant, "Game Statistician didn't record assists!). I wonder how they came up with them?
The +/- stat has been brought up in a recent discussion where it was mentioned that, somewhere, it has been recorded as far back as 63/64. I remember watching this show back in the 90s where they said that they had a variation of that up until a certain time, then they went with it as we know it now. Maybe I remembering that incorrectly. So it only really started in 67/68, along with shots (players)? The reason I ask is, someone mentioned to me that Howe got 20 something shots in a game against his brother Vic back in the 50s, and that was a record for one player at the time. Unofficial record, I assume.
How about goalies? Early on they had it so that you could play 66 1/3 games! Now the way I looked at that is, 67 games, but one of them was only a period!
Save %? Isn't there a book that has it for all the goalies from 67 on, yet Hockey-Reference only has it from 83/84 > present
a couple short answers - sv% has been reconstructed from actual game sheets by Sebastien Tremblay in his book "goaltenders - the expansion years". I posted that info in threads in this section. that covers 1968-1979. The 1980-1983 seasons have been reconstructed by the HSP. 1954-1968 were put together by Edward Yuen of my hometown, Regina, using newspapers, and used by The Hockey Compendium in their 2001 book. (he did some years in the 70s, too, but those have been rendered obsolte by more reliable stats now)
as for early GP and assists, these have been put back together by painstaking research. It's not just the NHL's inagural season, it's the whole history of the NHA, and even the EC(A)HA before it! Assists are given out by reading newspaper reports about the game. the statements, I imagine, would have to be descriptive enough to come to the conclusion that an assist was deserved. No doubt a lot of assists are lost to the sands of time forever. But the ones for which proof exists, should be remembered statistically.