Bo Levi Mitchell records one of the best debuts ever in battle of rookie starters Friday

With Kevin Glenn still hurt, the Calgary Stampeders seemed to hold out hope that Drew Tate would be recovered enough to start Friday's game against Winnipeg, waiting until just before the game to announce that Bo Levi Mitchell would be starting instead. The Stampeders got almost the best imaginable performance from Mitchell, though, who outdueled Justin Goltz (who started in place of Buck Pierce, making this the first CFL clash in 17 years where two quarterbacks received their first professional start in the same game) en route to a 37-24 victory. In fact, Mitchell's first start was one of the best ever, and well ahead of many current and future Hall of Famers. It even could present Calgary with an interesting conundrum in the weeks and months ahead: with three capable quarterbacks in Tate, Glenn and Mitchell, who fits in where, and which one of them will be protected in the Ottawa expansion draft after this season?

How good was Mitchell's play? Well, he put up maybe the best quarterbacking performances we've seen from anyone this season, completing 29 of 33 passes (87.9 per cent) for 376 yards and three touchdowns with no interceptions. There aren't many games from veteran QBs that come close this year. Saskatchewan's Darian Durant threw for more touchdowns (four) and almost as many yards (347) in last week's 37-0 blowout win over Hamilton, but was less efficient, completing 20 of 32 passing attempts (62.5 per cent). Toronto's Ricky Ray was even more efficient than Mitchell in the Argos' win over Winnipeg last week, setting a CFL completion percentage record by completing 19 of his 20 attempts (95 per cent), but his yard (286) and touchdown (two) totals were lower, as he left the game partway through after suffering an injury. The duel between Ray and the Tiger-Cats' Henry Burris from Week One also doesn't quite stack up, as they threw for 368 and 361 yards with four and three touchdowns respectively, close to Mitchell's totals, but only completed 70.6 and 64.9 per cent of their passes. Given that, there's a strong case for anointing Mitchell's game Friday as the best all-around passing performance this season.

What about the historical context? Well, let's compare Mitchell's first CFL start to some of the league's best current quarterbacks. It's tough to find game-by-game stats from too far in the past, but this can be done for many of the league's current top passers. We don't have a total passing line for Anthony Calvillo in his debut for Las Vegas in Week One of the 1994 season (that's so long ago has the score, but no stats), but we know from this Deseret News recap (thanks, Dan Toman!) that Calvillo started four-of-16 for 46 yards in the first half, but went eight for 12 after the break with three touchdowns, giving him a line of 12-for-28 (42.9 per cent) with three touchdowns and an uncertain amount of yards. (Update: via Richard Obrand and Steve Daniel at the CFL office, Calvillo had 170 passing yards in that game, and threw three touchdowns without an interception.) Travis Lulay? He earned his first start for B.C. in Week Four of 2010, completing 26 of 40 passes (65 per cent) for 330 yards, but throwing two interceptions in a loss to Toronto.

Some got off to better starts than those. Burris made his starting debut with Calgary in Week Four of the 1999 season after Dave Dickenson went down, completing 19 of 28 passes (67.9 per cent) for 269 yards and two touchdowns in a victory over Montreal. Durant's first start came in Week Three of the 2008 season, where he completed 23 of 32 passes (71.9 per cent) for 339 yards and two touchdowns to lead Saskatchewan to a win against Hamilton. Ray started for the first time for Edmonton against B.C. in Week Five of the 2002 campaign, going 21 for 28 (75 per cent) for 277 yards and four touchdowns to help the Eskimos to victory. There are some great (Ray, Durant) and some not-so-great (Calvillo, Lulay) performances in there, but Mitchell's would seem to be above all of them. It helps that he's had more time to learn the game as a backup than many (he's been with Calgary since the start of the 2012 CFL season: by contrast, Calvillo started for Las Vegas only weeks after making the team), but this was still an incredible showing, and one that should provide great hope for Mitchell's future.

The key question now for Calgary is what they do with their quarterbacks going forward. One start's an exceptionally small sample size, but Mitchell's performance suggests he has star potential. He's also only 23, which might make him a better investment for the long term than Tate (29, but often injured) or Glenn (34). All three of the Stampeders' quarterbacks can clearly play, which is a good problem to have considering the lack of QB depth elsewhere in this league, but it could give head coach and general manager some tough decisions to make about who should start. It's going to be tough to sit Mitchell after a showing like that, but Hufnagel may still elect to do so in favour of one of the more experienced options if they're healthy. The biggest issue may come after the season though, as the Stampeders can only protect one quarterback in the expansion draft. Before Friday's game, it seemed clear that would be Tate. Mitchell's incredible debut may have altered that equation dramatically.