That giant sucking sound you've heard over the past decade or so has been the offense draining out of Major League Baseball. This has been happening for a variety of reasons, from obvious ones such as the heightened focus on the removal of performance-enhancing drugs from the game, to harder-to-spot ones such as increased focus on team defense, bullpen specialization, ground-ball pitchers and infield overshifts.
As a result, the number of runs scored per game has plunged since the dawn of the century. Using traditional counting statistics, the offenses of today wouldn't seem to measure up to the juggernauts of the early 2000s. Once you adjust for the run-scoring environment, however, it quickly becomes clear that we are currently witnessing one of the truly great American League offenses in recent memory in the Toronto Blue Jays.
After their most recent blowout of the Los Angeles Angels, the Jays have scored 670 runs in 124 games (5.40 per game), with a .332 team on-base percentage and .445 slugging percentage. All those figures currently lead the American League, as does their context-adjusted 114 OPS+. Since 2000, 12 clubs (including this year's Jays) -- less than one club per season -- have posted a seasonal 114 OPS+ mark. Of those 12, nine (again including the '15 Jays) also led the league in runs scored. Below, we rank those nine clubs by the number of standard deviations they are above that year's AL average in runs scored.
As you can see, in terms of the average variance from the norm in runs scored, the Jays have the premier AL offense since 2000. In fact, being more than two-and-a-half standard deviations above the norm in anything is a really big deal. Two-thirds of the values in any range are within one standard deviation of the average; only the top and bottom one-sixth lie outside it. By this measure, the Jays are the elite of the elite since the turn of the century.
So what makes the Jays so good? There are a number of contributing factors. Let's take a closer look: