Assuming WAR is a useful measurement of pitching prowess, I notice that the Rays top three starters have WAR's of 1.7, 1, and .7. The Sox top three are 1.1, .7, and .6. However, the Sox 4 and 5 starters have WAR's of .6 and .3, and the Jays 4 and 5 are sort of undetermined.
Thanks to recent dingers given up, Barnes WAR has dropped to .8 and Whitlock's to .6. Then Valdez at .3, Sawamura at .2, and Ottavino at -.2.
The Jays bullpen WAR's are: Chatwood .9; Castro .6; Payamps (a name to conjure with) .5; Bergen .5; Phelps .4.
Season to date, Toronto's ERA is 3.82 and the Sox 3.89.
Season to date, the Sox run differential is +41 and the Jays is +40. That one run edge is because the Sox have scored 224 runs to the Jays 203.
In other words, the Sox have better hitting, the Jays better pitching, and overall these two teams are about even steven. Sox are 1.5 game ahead.