I think it's down to Thurmond and Ewing for this spot, with Wallace next after those two. I was initially ready to vote Thurmond here earlier, but Trex made a valid point that I may have been giving Thurmond too much credit relative to the other candidates based on available data. I think Thurmond was a slightly better man to man defender (in fact, the great centers of that era's averages against Thurmond is probably his biggest selling point), but Ewing was a significantly better team defender. Ewing anchored an elite defense for about a decade, and in 92-93 and 93-94, the Knicks ran out one of the best defenses in the history of the league. Thurmond and Ewing's respective era's are the two best eras for centers...but in a league with fewer teams, Thurmond had to go up against the other elite bigs more times over the course of a season...so it somewhat comes down to what you value more in this project, man D or team D, and to what degree.
As a comparison, I personally think both Olajuwon and Ewing were better PnR/switch defenders than David Robinson (and Thurmond), with Ewing incredibly underrated in that department, especially pre-1998. To Robinson's credit, he was probably better in the Pnr/switch on plays where the guard drove all the way to basket, but Ewing and Olajuwon were better on plays where the offensive player tried to juke around the perimeter before taking a jump shot. I can vividly remember Ewing making game and playoff series winning blocks/shot alterations on players like Tim Hardaway and Reggie Miller (among others) all the way out at the 3 point line.
(Here's one example: block on Hardaway's 3PA, end of the game -
)
I was expecting Thurmond to have a massive rebounding edge, which also factored into my earlier placement of Thurmond, but after a closer look at the data, their per 100 possession and TRB% stats (where available) are quite similar. We don't have this data for Thurmond's entire career, so while I'll still give Thurmond the edge here, it's probably not quite as substantial as I was thinking. Forgotten about Ewing is that even though he had an offensive debacle of a series, he did set two defensive records in the 94 finals: most blocks in a finals game and most blocks in a 7 game series (in a series with limited shot attempts, and neither team scoring more than 93 points in any of the games). Ewing also had superior longevity and did all of his defensive damage prior to 1999 while being his team's primary scoring option, which makes his sustained impact on that side of the ball even more impressive.
I'm going to vote Ewing here even though my gut said Thurmond when the vote on centers first started, though I can see a case for Thurmond and wouldn't disagree with anyone who voted him. I don't see an argument for Wallace yet that doesn't hinge on DPOY and 1st Team All D selections (both of which are highly subjective). Ewing and Thurmond were both better man defenders, and I think Ewing was at least equal as a team defender to Wallace, probably better, with clearly better longevity.
