Title says it all, doesn't it? I'll cut to the chase.
Inge is 2nd in the AL in home runs for 3B, 3rd for RBI's and middle of the pack in batting average. As always, those numbers alone do not tell the whole story. Basically, he is a Fangraphs.com and Baseball Prospectus All Star. He has the third highest wOBA among 3rd Baseman, and is barely behind Scott Rolen for that honor. He is second in wRAA, fourth in wRC (Runs Created) and is second in Isolated Power. And, he makes up for being 4th in OBP and in the BB/K rate with being second in slugging % and OPS. Notice a pattern? He is top 4 in every single offensive statistic, other than batting average (which is an ancient statistic that I wouldn't even use to tout Miguel Cabrera's candidacy for the All Star game). The only other 3rd baseman to also have that honor is Evan Longoria, the obvious choice to start in the game. Among Inge's closest peers offensively are Scott Rolen, Michael Young, and Chone Figgins, with Rolen posing a legit argument that he is having a better offensive season.
Defensively, though, its not close. Inge is second to Joe Crede in UZR (Ultimate Zone Rating in Runs Above Average), 2nd to Adrian Beltre in RngR (Range Runs above average) and has a better RF/9 than both Rolen and Young. Figgins would get the nod in that stat.
In terms of overall value, it is also not close. Inge currently has the 3rd highest WAR in all of the AL, and is second behind the great Longoria for 3B. He has a WAR of 3.2. A full season of 4.0 WAR is considered good.
So, let's break this down. Joe Crede has probably been the best defensive 3B in the AL, but he trails Inge in nearly every offensive stat. Inge has at least tied Michael Young in offensive production, and Young has the lowest UZR of any qualified 3B in the AL. His terrible defense alone takes him out of the discussion. Basically, it comes down to Scott Rolen and Chone Figgins. Here are how the three compare:
Rolen has the better VORP, EQA, wOBA, and batting average of the three. Inge has the better SLG, OPS, ISO, wRAA, and far and away is the better defensive 3rd Baseman with a UZR of 9.7 compared to Rolen's 1.1 and Figgins 1.4. Figgins leads in OBP, wRC, and Range. Based on this breakdown, it is pretty clear that Rolen and Inge are #2 and #3 for AL third baseman. Rolen has been the better offensive player of the two, but Inge has created a much larger discrepency with his vastly superior defense. The difference separating them for EQA and wOBA is miniscule, at best. And, Inge brings an added advantage of power by hitting 12 more home runs than Rolen has this year. Additionally, he has been worth 1 additional win this year according to the WAR stat.
When you combine an offensive performance that places him in the top 4 in nearly every major offensive statistic for AL 3rd baseman, and when you add in that he has been the 2nd best defensive 3rd baseman in the AL, the facts support the argument. Other than Longoria, he is the only 3rd baseman in the AL that can say he is a top 4 offensive 3B and a top 4 defensive 3rd baseman. The man should be, and better be playing in St. Louis for the All Star game.