Strategy session: Ranking draft prospects by tiers
By Chad Ford
ESPN Insider

Every time I put up a new mock draft (look for our newest one on Tuesday), I get a lot of feedback from readers who wonder how I put it together and how it differs from the Top 100.

This is how it works: Both pieces are reported pieces. In other words, I talk with NBA scouts and executives to get a sense of:

A. Which teams like which players (mock draft).

B. What the consensus is among all 30 NBA teams about who the best players in the draft are (Top 100).

I use the word consensus lightly. Often, even NBA GMs and scouts employed by the same team can't agree on their internal rankings of players.

"I fight with my scouts constantly," one prominent GM told me. "Everyone has their own ideas, their own preferences, their own methodology. There really is no consensus and, I hate to say it, I'm not sure there's even any real right or wrong."

Obviously both lists are imperfect because the draft is a bit of an inexact science. NBA teams do more than just watch prospects play games. They work out players, give them psychological tests, do background checks and conduct personal interviews. All of this factors into the process and could change opinions.

Factor in the ranking wars with another age-old debate -- do you draft for need or for the best player available -- and it's no surprise that the draft can be so volatile. Many teams take into account holes at certain positions (i.e. the team has no small forward) or coaching/system preferences (i.e. the Suns draft players who can fit into Mike D'Antoni's up-tempo shoot-first-ask-questions-later system) when making their decisions.

To make sense of disparate rankings and debates over team needs, several teams who have been very successful in the draft employ what I call a "Tier System" of ranking players. Instead of getting an exact order from one to 60 of the best players in the draft, they group players, based on overall talent level, into tiers. Then, the team ranks the players inside each tier based on team need.

This system allows teams to draft not only the best player available, but also the player who best fits a team's individual needs.

So what do the tiers look like this year? After talking to several NBA GMs and scouts who employ this system for their teams, I've put together these tiers. (Because the teams do not want to divulge their draft rankings publicly, the teams have been left anonymous.)

TIER 1
Greg Oden
Kevin Durant

Note: There seems to be a clear preference for Oden among GMs, but everyone agrees both players have superstar potential and are clearly the consensus top two in the draft.

TIER 2
Corey Brewer
Mike Conley
Jeff Green
Al Horford
Yi Jianlian
Brandan Wright

Note: One team expanded this tier to include all of Tier 3, essentially making Tier 2 the third through 12th picks, but most everyone else made a cut right before the players in Tier 3. I'd also note that there was near consensus that Horford is the third-best player in the draft.

TIER 3
Spencer Hawes
Joakim Noah
Al Thornton
Julian Wright

Note: Tier 3 represents the final four players in the top 12. Every team I spoke with had the same 12 players in the top 12. That's a pretty amazing consensus for this deep in the draft. It also shows the depth of the draft itself. Last year, Tiers 1, 2 and 3 consisted of a total of seven players.

TIER 4
Javaris Crittenton
Acie Law
Rodney Stuckey
Nick Young
Thaddeus Young

Note: There was a clear preference for the Youngs in Tier 4, with one team saying its Tier 3 was expanded to include both players. Not everyone had Crittenton or Stuckey in Tier 4; some had them in Tier 5.

TIER 5
Morris Almond
DeVon Hardin
Josh McRoberts
Gabe Pruitt
Jason Smith
Tiago Splitter
Sean Williams

Note: The consensus really starts to break up here. Some have Smith and Williams ranked higher. Some have McRoberts and Hardin ranked lower.

TIER 6
Arron Afflalo
Marco Belinelli
Derrick Byars
Daequan Cook
Glen Davis
Jared Dudley
Nick Fazekas
Rudy Fernandez
Marc Gasol
Taurean Green
Petteri Koponen
Marcus Williams

Note: If you do the math, 36 players are on the list. Why 36 guys for 30 slots? I included in Tier 6 every player that a team told me was in its top 30. I suspect had I polled every team, this number would have expanded to around 40 players.

So how does the tier system work?

A team ranks individual players inside each tier according to team need. So, in Tier 2, if point guard is the biggest need, Mike Conley is ranked No. 1 in Tier 2. If power forward is the biggest need, Al Horford or Brandan Wright is ranked No. 1 depending on individual team preference. (See table for an example.)

Here's an example:

TEAM B

Needs: PG, SG, PF

Tier 2
1. Mike Conley
2. Corey Brewer
3. Al Horford
4. Brandan Wright
5. Yi Jianlian
6. Jeff Green

TEAM A

Needs: PF, SF, PG

Tier 2
1. Al Horford
2. Brandan Wright
3. Yi Jianlian
4. Corey Brewer
5. Jeff Green
6. Mike Conley

The rules are then pretty simple. You always draft the highest-ranked player within a given tier. So, for example, if the Bulls are drafting No. 9 (Tier 3 territory) and Corey Brewer is on the board (a Tier 2 player), they take him regardless of position. The rule is that you never take a player from a lower tier if one from a higher tier is available. So if the Bulls had Spencer Hawes ranked No. 1 in Tier 3, they'd still take Brewer, even though center is a more pressing need.

BULLS

Team needs: PF, C, SF

Tier 2
5. Corey Brewer
6. Jeff Green

Tier 3
1. Spencer Hawes
2. Joakim Noah
3. Julian Wright
4. Al Thornton

Here's another example (see table):

What this system does is protect teams from overreaching based on a team need. The Bulls won't pass on a clearly superior player like Brewer to fill a need with Hawes. However, the system also protects a team from passing on a player who fits a need just because he may be ranked one or two spots lower overall.

Let me give you an example from the worst-drafting team over the last few years, the Atlanta Hawks.

Hawks GM Billy Knight has stated that he takes the best player on the board, regardless of team need. He's proven that the last few years by taking Marvin Williams ahead of Chris Paul and Deron Williams in 2005, and taking Shelden Williams ahead of a point guard such as Rajon Rondo in 2006.

A source formerly with Atlanta's front office told me that the Hawks had Marvin Williams ranked No. 1, Andrew Bogut ranked No. 2, Deron Williams ranked No. 3 and Paul ranked No. 4 in 2005. So on draft night, Knight took Marvin Williams with the No. 2 pick after the Bucks selected Bogut No. 1 overall.

In a tier system, however, the source conceded that all four players, in his mind at least, would have been Tier 1 players -- in other words, the Hawks thought all four had equal long-term impact potential. If the Hawks had employed a tier system, they would have ranked inside the tier based on team need and fit, rather than just ranking the prospects from one to 30.

In that case, the Hawks likely would have ranked either Bogut (they needed a center) or Deron Williams (they still need a point guard) No. 1. Marvin Williams actually would have been ranked No. 4 under that scenario.

In any case, like every draft system, the tier system isn't perfect. But the teams that run it have found success with it. It has allowed them to get help through the draft without overreaching. Compared to traditional top-30 lists or mock drafts, it seems like a much more precise tool of gauging which players a team should draft.