Earlier today, I was wondering whether Justin Verlander's last nine games were the best nine games for a pitcher in the history of the Tigers. Tigers broadcaster Dan Dickerson reported via Twitter that the only other Tigers pitcher with nine consecutive games of seven or more innings and two or fewer earned runs was Hall of Famer Hal Newhouser in 1945. Prince Hal pitched ten such games between June 3, 1945 and July 12, 1945. I will add that right-hander Frank Lary also pitched nine consecutive games meeting the above criteria, but it spanned two seasons - 1956 and 1957.
Taking it a little further, Newhouser had nine complete games in ten starts and even added two saves out of the bullpen during his streak. Verlander has had only two complete games out of nine, but that's the way pitchers are used in the age of specialization. This makes it difficult to compare pitchers from different eras. However, Verlander has been more dominant during his streak (0.75 ERA and 0.78 WHIP) than Newhouser was in 1945 (1.38 ERA and 1.02 WHIP).
Verlander has also had a much higher strikeout rate (9.2 strikeouts per nine innings) than Newhouser (5.7) but that's another era difference. Pitchers didn't strike out as many batters in the 1940s as they do today. The league average pitcher strikes out seven per nine innings in 2011 compared to just over three in 1945.
Even considering differences in eras though, one can make a strong case that Verlander's last six weeks has been the best stretch of pitching in the history of the Tigers.