Opening Tip: Calderon a major upgrade over Collison?

The point guard who wasn't good enough to close games in Dallas helped the Los Angeles Clippers pull off a couple of monster comebacks against the Dallas Mavericks this month.

It would be bad enough to blow big leads against a team led by Chris Paul. But the fact the Los Angeles Clippers' comebacks from 17-point deficits occurred with Darren Collison on the court makes them even more bitter pills to swallow.

Collison was a Dallas reject, a point guard the Mavs replaced with a pair of 37-year-olds last season and showed no interest in re-signing, running the show when the Clippers slammed the door with game-ending runs of 16-2 and 23-4. Collison won his individual matchup in both meetings with the Mavs, averaging 16 points and seven assists.

It's almost enough to make you wonder how much the Mavs really upgraded at point guard by signing Jose Calderon to a four-year, $29 million deal this summer. Actually, it was more than enough for a couple of particularly annoying Collison apologists to troll me about it on Twitter, prompting me to agree to crunch some numbers for an unbiased comparison.

Truth be told, it's tough to make a statistical case that Calderon is much better than Collison was during his one-season stint in Dallas. It's especially difficult to do with traditional stats.

Collison averaged 12.0 points, 5.1 assists, 2.1 turnovers and 1.2 steals while shooting 47.1 percent from the field for the Mavs. Calderon's numbers this season: 12.1 points, 4.8 assists, 1.2 turnovers and 1.2 steals, shooting 46.7 shooting percentage. The biggest differences are the reduced turnovers and improved 3-point shooting (Calderon .467, Collison .353).

Advanced stats? Collison had a slightly higher player efficiency rating (16.37 to 16.14). Collison's defensive rating (105.7 points per 100 possessions) is a little less than a point lower. Calderon has the better offensive rating (108.0) by more than four points, but he also had the benefit of playing with a healthy Dirk Nowitzki and Monta Ellis instead of O.J. Mayo.

Oh, but the Mavs identified upgrading point guard as a major summer need to help solve their crunch-time woes. The early returns from Calderon have been mixed.

With the score within five points in the final three minutes, Calderon tends to become even more of a complementary player than normal, moving the ball and spacing the floor. In those situations, he has seven points, seven assists and only one turnover in 42 minutes, having attempted only five shots, all 3-pointers, and making only one. Calderon's net rating (offensive rating minus defensive rating) in such instances is minus-10.6, but the Mavs tend to replace him for defensive possessions as often as possible.

In the same situations last season, Collison averaged 22.7 points per 48 minutes, but that's because he made clutch free throws. His shooting percentage in the final three minutes of close games was a dreadful 29.2, and his per-48 turnover average (4.9) was almost as high as his assists (5.4). Collison's final-three-minute clutch net rating: minus-11.0.

There's a critical intangible factor in play here, too. Collison couldn't earn the trust of coach Rick Carlisle and Nowitzki, who both wanted Calderon and have believed in the veteran point guard from the moment he signed with the Mavs.

This really comes down to wins and losses. The Mavs were five games under .500 with Collison as a starter last season. They're seven games over .500 when Calderon starts.

In those late, close games -- and we're using games within five points in the final three minutes -- they're 10-8 with Calderon and 6-17 with Collison.

The meltdowns against Collison's Clippers certainly stung, but not enough to make the Mavs have second thoughts about signing Calderon to a deal that started at 170 percent of the salary Collison made during his one-and-done Dallas stint.