The Jays hot streak has come mainly with Vernon Wells out of the lineup. Vernon went on the DL May 10th, and since a rainout on the 11th the Jays are a scorching 13-5. During this stretch they've scored 78 runs while allowing 49, or 4.33/2.72 runs for and against per game. That first number is nothing to write home about, even with yesterday's 12 run outburst (which if you throw out put the Jays slightly below their season average of 3.8 runs per game during a 17 game stretch). No, its the second number that is fantastic - over a full season at that pace the Jays would allow 441 runs, which at a guess would be one of the top ten numbers in the live ball era (if not better). Lets look ever so superficially back at those 18 starts.
Of course various caveats apply here - this sample size is small, and somewhat arbitrary in length and start. Plus the Jays face the Royals, the worst offensive team in the AL, and Cleveland, Oakland and Anaheim have all been middle of the pack (Philly's been fantastic).
With that being said, if you throw out David Purcey's spot start, the Jays have allowed 39 runs in 17 games, or about 2.3 runs a game. Thats out of this world. The Jays have allowed 3 or fewer runs in 14 of their last 18 games overall, a remarkable feat. The Jays are allowing 3.55 runs per game on the season, second best in the American League (only the A's have been better).
What is just as amazing is the innings the Jays are getting from their starting pitching. In the 18 game stretch, only three times did a Jays pitcher fail to go five and two-thirds innings - Purcey went three against the Phillies, Marcum went one because of rain, also against Philadelphia, and McGowan went five against the Twins. Jesse Litsch has pitched at least seven innings in four of his last five starts, Marcum has only pitched fewer than six innings twice all season (the one inning game and a game against Detroit where he got pulled with two out in the sixth) - he's gone at least 6.2 innings in nine of his eleven starts. Despite his control problems Dustin McGowan gone 6.1 innings or more in four of his last six starts, and A.J. Burnett has worked at least six innings in six of his last seven starts, with the lone exception coming Monday against the A's, when he went 5.2. Roy Halladay leads the Majors in innings pitched, of course, and has not pitched fewer than six innings in a start all year - he's pitched eight or more innings in seven of eleven starts.
In any event, I guess this is a long way of saying that the Jays probably don't need seven relievers, and that their pitching is really, really, good.