Top players ever - The Joehoo List

**joehoo**:

Quote from: "BRockin25"

How are win shares measured? this is the real key

And...what about playoff win shares?

Well, I can provide you with how win shares are measured, but does it really matter?

For example, we can start with all of the ideas that many of the non-idiots have on this board about who led what teams... and almost to a man, win shares seem to display our original thoughts.

Quote from: "basketball-reference.com"

Calculating Win Shares

Note: This article was edited on April 26, 2006. I changed the way defensive Win Shares are credited to individual players.

Introduction

Stealing a page from Bill James, I decided to attempt to calculate basketball Win Shares. Due to data limitations the current system only works for the seasons 1977-78 forward, but at some point I hope to modify the system for seasons prior to 1977-78. This article will describe how I came up with the Win Shares system for basketball.

What is a Win Share?

A Win Share is worth one-third of a team win. Win Shares are assigned to players based on their offense, defense, and playing time. If a team wins 60 games, there are 180 Win Shares to distribute among the players. This is always true; if a team wins n games, then there are 3n Win Shares to allocate to the players.

Splitting Win Shares Between Offense and Defense

Splitting Win Shares between offense and defense is based on something called marginal points. To calculate marginal points scored, do the following (I will use the 2003-04 San Antonio Spurs as an example):

Calculate league points scored and league possessions. Calculating league points scored is straightforward. In 2003-04 the league scored 222097 points. Possessions are estimated using a formula presented by Dean Oliver in Basketball on Paper (please see Oliver's book for complete details). In 2003-04 this works out to 215776.07 league possessions.

Calculate the league's points per possession. In 2003-04 the league scored 222097 / 215776.07 = 1.02929 points per possession.

Calculate the team's expected points scored. Expected points scored are (league points per possession) * (team offensive possessions). The Spurs had an estimated 7330.74 offensive possessions, so they were expected to score 1.02929 * 7330.74 = 7545.46 points.

Calculate marginal points scored. Marginal points scored are points scored minus 0.92 times expected points scored. For the Spurs this is 7501 - (0.92 * 7545.46) = 559.18 marginal points scored.

The next step is to caclulate marginal points allowed. To do this:

Calculate the team's expected points allowed. Expected points allowed are (league points per possession) * (team defensive possessions). The Spurs had an estimated 7353.42 defensive possessions, so they were expected to allow 1.02929 * 7353.42 = 7568.80 points.

Calculate marginal points allowed. Marginal points allowed are 1.08 times expected points allowed minus points allowed. For the Spurs this is (1.08 * 7568.80) - 6909 = 1265.30 marginal points allowed.

Marginal points are the sum of marginal points scored and marginal points allowed. For the Spurs this is 559.18 + 1265.30 = 1824.48 marginal points. In order for the system to work, there must be a relationship between marginal points and team wins. The relationship is this: 1 win is equal to m marginal points, where m is equal to one-third of the league average points per game for a team. In other words, based on their marginal points the Spurs would have been predicted to win 1824.48 / (93.4 / 3) = 58.6 games. They actualy won 57 games, for an error of 57 - 58.6 = -1.6 wins. If marginal points are used to predict team wins for all teams since 1977-78, the root mean squared error (rmse) of the predictions is 3.86 wins.

Aside: Where did the 0.92 and 1.08 multipliers come from?

Good question. I figured a team made up of marginal players would win about 10 percent of their games, so I solved the following equation for x:

(1 - x)**14 / ((1 - x)**14 + (1 + x)**14)) = 0.10

The value of x is roughly 0.08, so 1 - x = 0.92 and 1 + x = 1.08.

The Spurs won 57 games in 2003-04, so the team has 3 * 57 = 171 Win Shares. To determine how many Win Shares to allocate to the offense and defense, divide marginal points scored (or allowed) by marginal points and multiply by Win Shares. For the Spurs offense this is (559.18 / 1824.48) * 171 = 52.4 Win Shares, while for the Spurs defense this is (1265.30 / 1824.48) * 171 = 118.6 Win Shares.

In order to prevent teams from having too few or too many Win Shares credited to their offense, at least 25% and at most 75% of a team's Win Shares must be credited to the offense. This rule did not affect the 2003-04 Spurs, as 52.4 / 171 = 30.6% of the team's Win Shares were credited to the offense.

Crediting Offensive Win Shares to Players

Offensive Win Shares are credited to players based on Dean Oliver's Offensive Rating. Offensive Rating is an estimate of the player's points produced per 100 offensive possessions. The formula is quite detailed, so I would point you to Oliver's book Basketball on Paper for complete details. The process for crediting offensive Win Shares is outlined below (using Tim Duncan of the 2003-04 Spurs as an example):

Calculate the Offensive Rating for each player. In 2003-04, Tim Duncan's Offensive Rating was 107.385.

Calculate offensive possessions for each player. Once again, I would point you to Oliver's book for complete details on calculating player offensive possessions. Tim Duncan had an estimated 1373.19 offensive possessions in 2003-04.

Calculate marginal offense for each player. Marginal offense is equal to (player possessions) * ((player Offensive Rating) / 100) - 0.92 * (league points per possession)). For Tim Duncan this is (1373.19) * ((107.385 / 100) - 0.92 * (1.02929)) = 174.26. Note that any player with negative marginal offense gets zeroed out at this step.

Calculate team marginal offense. The team total for the 2003-04 Spurs is 647.299.

Credit offensive Win Shares to the players. Offensive Win Shares are credited using the following formula: ((player marginal offense) / (team marginal offense)) * (team offensive Win Shares). Tim Duncan gets credit for (174.26 / 647.299) * 52.4 = 14.1 offensive Win Shares.

Crediting Defensive Win Shares to Players

Crediting defensive Win Shares to players is based on Dean Oliver's Defensive Rating. Defensive Rating is an estimate of the player's points allowed per 100 defensive possessions. I know I'm sounding like a broken record, but please see Oliver's book for further details. Here is the process, once again using Tim Duncan as an example:

Calculate the Defensive Rating for each player. Tim Duncan's Defensive Rating in 2003-04 was 88.501.

Calculate marginal defense for each player. Marginal defense is equal to (player minutes played / team minutes played) * (team defensive possessions) * (1.08 * (league points per possession) - ((player Defensive Rating) / 100)). For Tim Duncan this is (2527 / 19755) * 7353.42 * ((1.08 * 1.02929) - (88.5001 / 100)) = 213.18. Note that any player with negative marginal defense gets zeroed out at this step.

Calculate team marginal defense. The 2003-04 Spurs team total is 1245.79.

Credit defensive Win Shares to the players. Defensive Win Shares are equal to ((player marginal defense) / (team marginal defense)) * (team defensive Win Shares). For Tim Duncan this is (213.18 / 1245.79) * 118.6 = 20.3 defensive Win Shares.

Putting It All Together

The final steps of the process combine offensive and defensive Win Shares such that the final result is an integer. They also ensure that player Win Shares sum to three times the team's win total. Here are the remaining steps:

Add offensive and defensive Win Shares. Tim Duncan's total is 14.1 + 20.3 = 34.4.

Separate the figure above into Win Shares and partial Win Shares Tim Duncan had 34 Win Shares and 0.4 partial Win Shares.

Compute final Win Shares. Sort the team's players by descending partial Win Shares. If the sum of player Win Shares does not equal team Win Shares, add one Win Share to each player on the sorted list until the two are equal. For example, the player Win Shares for the 2003-04 Spurs sum to 164. The Spurs as a team had 171 Win Shares. Therefore, the players with the 7 highest partial Win Shares get one Win Share added to their total. This did not affect Tim Duncan, so his season total remains 34 Win Shares.

Here are the final Win Shares totals for the 2003-04 San Antonio Spurs:

Name WS

Tim Duncan 34

Manu Ginobili 24

Tony Parker 20

Rasho Nesterovic 20

Hedo Turkoglu 18

Bruce Bowen 15

Robert Horry 12

Malik Rose 10

Jason Hart 5

Devin Brown 5

Kevin Willis 3

Ron Mercer 2

Charlie Ward 2

Anthony Carter 1

Shane Heal 0

Matt Carroll 0

Alex Garcia 0

This is my first attempt at basketball Win Shares, so this should be considered a work in progress. If you have any comments or questions, plase send me some feedback.

As far as playoff win shares, you can barely find steals PER GAME for the playoffs. Playoff stats are just not advanced.

Two things:

1. You can go down this road of questioning things if you want, but... I have the experts on my side, and, while you are a smart person, on your side are the questions of someone much less qualified than the person who formulated win shares...

2. When was the last time you saw a team play 82 games one way and then drastically change their entire philosophy of team roles in the playoffs??

**BRockin25**:

I wasnt "questioning" win shares but Im wasnt going to accept them as authoritative until I actually knew how they were calculated

The formula seems reasonable enough and does seem to accurately reflect regular season production

As far as your #2...teams dont necessarily "change their entire philosophy" but especially for players like Duncan, whose production always jumps in the playoffs, more statistical analysis should be made available. Not necessarily by you but by the basketball-reference.coms, 82games.coms, etc. bc I know its hard to find that stuff

**Legend34**:

I'd rather have Magic, Bird, Wilt, Russell, and Kareem than Jordan. Not to say that Jordan wasn't or was better than them, but personal preference.

**yiskobesogood2**:

Quote from: "joehoo"

Quote from: "BRockin25"

Why would Shaq rank over Duncan when Duncan has for "A" rings (your criteria) and Shaq has 3? Bc the statistics wll change that much? Or bc you happen to like Shaq? lol

The subjectivity of your formula is increasing by the day, against your original intent, but thats how most statistical compilations go

Well, because, the formula is this:

1. Productivity - PER x MPG

2. Championship win shares - So if you win 3 A-rings but you get 125 championship win shares, but the next guy wins 4 A-rings, but only gets 120.. you're winning in that category. It's a way of being more specific as to the role of a player. For example, Russell won 11 A-rings, but he never had a role similar to 06 Wade or 94 Olajuwon because the talent was more spread out... win shares addresses that. Now, they weren't recorded back then, but I can guarantee you if they were, Russell probably never breaks 40...

Let me provide examples by going to the team pages at basketball-reference...

1991 Chicago Bulls win shares:

Michael Jordan 56

Scottie Pippen 32

Horace Grant 29

2000 Los Angeles Lakers:

Shaquille O'neal 58

Kobe Bryant 33

Glen Rice 28

2007 San Antonio Spurs:

Tim Duncan 35

Manu Ginobili 28

Tony Parker 25

2008 Los Angeles Lakers

Kobe Bryant 39

Lamar Odom 27

Gasol/Bynum 27 (win shares are cumulative not average)

So a few ideas emerge here right off the bat to anyone with any sense of logic:

A) The idea that Kobe Bryant was the leader or even the co-leader of the 2000 Los Angeles Lakers is so far beyond ridiculous it's insane. As you can see, you can look at that and say to yourself "wow, he really did have no greater a role as compared to Shaq than Pippen did compared to Jordan.

B) You can presume that 00 Kobe and 91 Pippen are better than Ginobili and Odom and yet, Jordan and O'neal had less help than Kobe and Duncan because they take on an insanely greater role. Think about this... as good as Pippen, Bryant, Grant and Rice were, O'neal and Jordan accounted for approximately the same amount of production as Pippen/Grant and Bryant/Rice combined

C) Just like a ring is not a ring, an A-ring is not an A-ring... you can look at that and see why, in the same amount of rings, O'neal racked up more championship points than Duncan. Because he had more championship influence than Duncan.

3. MVPs

Now... as far as changing the list.... I'm really not changing it. When Dirk and Iverson and Wade and Kobe retire, we'll know where they will stand forever. For example, Wilt is not moving very much over the next 25 years, neither is Bird.

I'm simply catering to the whiners by taking certain guys out of the list so that they can see what the list more accurately measures.

.

3

Your arguement is fine. But...it comes down to basically watching the nba at this point. I mean if you watched the Lakers in 2000, like I did. You would know that Kobe was substantionaly better then Glen Rice. Not just 5 shares more. So its flawed in that aspect.

in 1999-2000 season Rice avged 15.2 ppg and 4.2 rpg 2.2 apg

Kobe avged 22.5 ppg and 6 and 5. thats greater on every level.

It just seems like 5 more win shares is worth less then say 7 more ppg 1 rpg and 2 apg.

**t-mac357**:

larry bird at 3 is quite a bit too high for him

and shaq and duncan both have 4 rings, period

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