BBR News: Win Shares Extended Back to 1951-52
Posted by Justin Kubatko on August 10, 2009
I have been working on a way to extend the Win Shares system to seasons prior to 1973-74 off and on (mostly off) for quite some time. Until last week, though, I had not been able to come up with a satisfactory solution. However, I had an idea last week that produced what I felt were satisfactory results, so today I would like to announce that the Win Shares system has been extended back to the 1951-52 season.
Full details are given in the article Calculating Win Shares, but I wanted to comment on a couple of things that people might view as flaws/bugs in the system.
First, if you take a look at the season leaders for Win Shares, you'll notice that the top ten are all from the 1960s and early 1970s. Does this mean the system is biased against modern players? No, it doesn't, because a key variable that needs to be considered is playing time. Here are the average minutes per game for the top five players in minutes per game over the years:
| Year | MP/G |
|---|---|
| 1959 | 40.5 |
| 1964 | 43.9 |
| 1969 | 44.4 |
| 1974 | 43.0 |
| 1979 | 39.9 |
| 1984 | 38.9 |
| 1989 | 39.4 |
| 1994 | 41.0 |
| 1999 | 41.0 |
| 2004 | 40.9 |
| 2009 | 39.5 |
As you can see, the top players from the 1960s and early 1970s were averaging about 4 more minutes per game than today's stars. For that reason alone we should expect the top players from that era to have roughly 10% more Win Shares per season.
Second, NBA record keeping was notoriously spotty in the early years. For example, there are 62 cases from 1950-51 to 1961-62 in which we know a player played for multiple teams, but we don't know his splits for those teams. In other words, we know his statistics for the entire season, but we don't know his statistics while playing for Team A and Team B. Because of this, some players with unknown splits will be missing Win Shares data.
August 10th, 2009 at 4:59 pm
Looking at the Yearly league leaders:
Wilt - 9 times
Kareem - 9 times
Jordan - 9 times
Nobody else has more than 5.
August 10th, 2009 at 7:57 pm
Fascinating. I'm always amazed at how underrated Kareem is.
August 10th, 2009 at 11:06 pm
Jason J,
What I find particularly interesting is the number of times Bill Russell led the league in defensive win shares -- nobody else here has more than five either, and ironically, it is also the number of championship rings he collected during his career.
One word: amazing.
August 11th, 2009 at 8:41 am
Jordan, Kareem and Wilt have led in Win Shares 9 times each and the next closest is 5. In the playoffs Jordan led in Win Shares 7 times and Russell 5 times. Those are the top 2 in the postseason.
August 11th, 2009 at 9:25 am
How crazy is it that Jordan led the league in playoff WS 7 times and only even made the finals 6 times? I know it's fully possible to play more games than either finalist without making the finals, but still... Actually looking at the list again I think Jordan is the only NBA player to lead the playoff WS without making the finals. And he did it twice.
August 11th, 2009 at 9:57 am
Some would argue that leading in WS in the playoffs is more valuable (since deeper in playoffs you go the more opportunity you have to generate WS) - interestingly 16 (/58) times has the reg. season ws leader also been PS Ws leader (MJ= 6 and Kareem 2nd with 3) - But that player has been the league MVP only 7 of those times (MJ 3 times, 2000 Shaq, 1983 Moses Malone, 1986 Larry Bird, and Kareem in 1980) - all of those players went on to be finals MVP, except Kareem who was injured and a young Magic rode Kareem's efforts to the title and finals MVP.
August 13th, 2009 at 11:48 pm
This just affirms my opinion that the public in the 60's did not fully appreciate Wilt Chamberlain in his prime. During Wilt's famous 61-62 season where he averaged 50.6 points per game [league leading] and 25.7 rebounds per game [league leading] (he had a points-rebounds-assists total of 78.7!), and was also first in Total rebounds and points, he led the league in Win Shares, games played, minutes played, field goals, field goal attempts, was second in field goal percentage, led the league in free throws made, free throws attempted, in player efficiency rating, was second in effective field goal pct, led the league in offense win shares, and was second in defensive win shares. However, MVP Bill Russell was second in Total Rebounds, second in minutes per game, and first in defensive win shares.
Clearly, Wilt Chamberlain was snubbed of the MVP in not only this case, but several others.
Thank you Justin for pointing this out in several mathematical ways.
August 14th, 2009 at 12:45 pm
I don't see how this proves anything about Chamberlain. Everyone already knows his numbers are overwhelming and he was the most dominant individual player ever. The question, which can never be proven one way or the other, is whether that made him more "valuable" than Russell. I wasn't around at the time but there is evidence that Chamberlain's raw statistics outweighed his actual contributions to the team, and vice versa for Russell.
August 21st, 2009 at 3:04 pm
I should add that I don't like the idea of untethering team Win Shares from actual team wins. To me, the great concept of WS, regardless the execution, was that all the numbers had to add up to creating actual wins. Though I realize it's different for hoops than baseball, in that combinations of players can enhance or work against each other, and thus in any one season a player's WS might not truly show his ability.
And I wonder if anything can be learned from seeing the difference between team WS and wins. Are there trends there, in the types of teams or particular players which win or lose more games than their aggregate WS? And the differences in the totals might be a clue as to how close our raw stats are to measuring everything we need to know about the game.
August 25th, 2009 at 12:11 pm
I would like to learn more about the system. it does not surprise me that Jabaar, Wilt and Jordan were the top three. They were the most dominant basketball players ever. The three of them.
August 26th, 2009 at 6:44 pm
I response to article number 9. I would like to say that mr Wilt Chamberlains numbers speak for themselves as a player. He contributed more to his team as a player. you could state that Mr Russell contributed more as a leader. However player contribution is measured in numbers. Some of the greatest coaches were lessser players. Evidently due to their study of the game. As for Bill Russells contribution its weighted heavily by playing for (the basketgball genius of) Mr Arnold Red Auerbach. The greatest mind in the history of the game at the professional level. He orchestrated the team moves and trades. Trading to get Mr Russell himself the final piece to their puzzle in the fifties.
September 27th, 2009 at 1:25 am
This shows who the true greats are...I wish the Kobe lovers could see this. He doesn't even register on the map, but we can see how great Lebron is going to be. This also affirms that the greatest player in history is Jordan, when all things are considered. If not the greatest, he is easily the best guard in history. Someone could make an argument for Wilt or Kareem, but I would argue that they never faced strong opposition from the likes of Shaq, Ewing, Hakeem, Malone, or the Admiral. Jordan dunked on all of these guys, and faced arguably the best power forward in history twice. Jordan also faced the best point guard in history and won. Jordan also had a knack for dropping 50 or 60 plus on the best teams and players in the league. He dropped 64 on Shaq, 63 on the Championship Celtics, 61 on the Bad Boy Pistons, and 55 on a Knicks team that went to the finals a year earlier.
October 18th, 2009 at 7:56 pm
Factual correction. Kareem did play against Malone.