The Toronto Blue Jays have the best record in baseball. The Toronto Blue Jays have played well for three weeks. Both statements are true, but one carries greater impact. Unfortunately, it’s the one most likely to lead you to the wrong conclusion.

When it comes to evaluating surprise teams, the important thing to do is to figure out what parts of the performance are potentially real, and which parts aren’t. For example, an analysis of the Florida Marlins on April 20 would have noted that their offense was being helped by a crazy-high empty batting average by Emilio Bonifacio, and some starters’ ERAs that didn’t match their peripherals. The parts that weren’t real outweighed the ones that were (such as the work done by Josh Johnson and Jeremy Hermida). Predicting a fade was a trivial exercise.

In the case of the Blue Jays, you have the best offense in the American League, one that’s posted a .283 team EqA and a circuit-pacing 133 runs scored. These numbers are being posted by a team that missed the postseason in 2008 largely because of a .253 EqA and its weak 714 runs scored. PECOTA pegged them for 712 runs, and I had them scoring 738. The Jays are scoring more than an extra run per game above expectations, despite making just one change of note to their lineup, and returning a whole bunch of players on the wrong side of 27.

That one change, however, can be considered “real.” Rookie Travis Snider can hit, and he’s off to a .278/.350/.537 start in a platoon role, playing against all right-handed pitchers and the occasional lefty, and starting almost exclusively in left field. The power he’s shown is real, and his contact rate and plate discipline are acceptable for a 21-year-old. He’s a significant upgrade over the hole that was in left field for this team a year ago.

The Jays’ other young left-handed hitter is raking as well. Adam Lind, locked in at DH, is bopping at a .314/.392/.512 clip. This is the hitter we expected him to be two years ago, and after a number of false starts and problems getting playing time, he’s flourished under Cito Gaston, hitting .293 with power (albeit a lack of walks) under the skipper a year ago, and putting it all together this season.

The two lefty bats are real, but it’s fair to say that the pre-season projections for the Jays factored in their presence. A look at the rest of the roster reveals a number of veterans having career months, performances that have been valuable, but offer little predictive value. Lyle Overbay has drawn 15 walks-five intentional-and roped eight extra-base hits in 52 at-bats, generating a 965 OPS. Marco Scutaro has 21 walks drawn and a .415 OBP to go with four homers and a .463 SLG. Rod Barajas is hitting .286, which doesn’t seem that impressive until you consider his career mark of .242. Aaron Hill is batting .371. Scott Rolen is batting .321. The top two guys off the bench, Kevin Millar and Jose Bautista, are hitting .351 and .344, respectively.

I’m not sure what percentage of those performances are sustainable, but I know it’s a low number. For a collection of middling veterans and guys who were waiver bait to be running over the league the way Overbay, Scutaro, Millar, Rolen, and Bautista are is a fluke. Hill is a good player whose return upgrades the Jays, but he’s 70 points above where he’ll end up as well. He, the two lefty bats, and maybe Alexis Rios-the auntie at the orgy with a .237/.298/.355 line that does at least include an uptick in his walk rate-are a viable core that should help score 4.5 or 4.6 runs per game the rest of the way. One or two of the veterans may hold on to their numbers and have a fluke season, but on the whole that group is going to lose 50 points of batting average and a ton of walks from here through the rest of the season.

The Jays’ pitching, so fantastic a year ago, has been effective in the face of several injuries this season. Ricky Romero, currently injured, and Scott Richmond have been effective, as has Brian Tallet in limited work. Brett Cecil should be up by midseason, and while the current rotation includes waiver bait Brian Burres and David Purcey‘s walk-the-park act, it’s not hard to see this as an eventual strength again, if not what it was a year ago. I’m impressed by J.P. Ricciardi’s ability to rebuild an effective rotation after the losses from last season, and I suspect that the 786 runs I predicted the Jays would allow will end up being a little high (noting that I missed on overall run levels by a bit as well). The rotation’s performance is real.

The Jays’ bullpen has also been better than expected. Off of last year’s fantastic performance, some regression seemed likely. Even with B.J. Ryan blowing up like a prop in a Jerry Bruckheimer film, the pen has been exceptional, holding opponents to a .190/.300/.335 line and ranking fourth in MLB in WXRL. Predicting the short-term performance of relievers is something of an exercise in dart-throwing, but the skill sets and peripherals of Scott Downs, Jason Frasor, and Jesse Carlson all provide reasons to be optimistic. The bullpen’s performance is real, especially if Ryan is kept away until healthy.

The Jays’ pitching is also once again benefiting from a strong defense. With the return of Aaron Hill, the team leads the AL in Defensive Efficiency and is fourth in Park-Adjusted Defensive Efficiency in the early going. The Jays have ranked highly in Defensive Efficiency for a few years now, bolstered by Rios and Vernon Wells in the outfield, and benefiting from occasional dalliances with John McDonald at shortstop. Only Snider is clearly subpar, though the evidence is mixed on Scutaro. This may not be the best defense in the league, but it is certainly an above-average group. This is also real.

Since he returned to the Jays’ bench last June, Cito Gaston’s record as manager is 63-41. It may be that the question of whether that number is real drives all the rest. For me, the key factor here has been his handling of Lind and Snider. You may recall that when Gaston was managing the Blue Jays in the 1990s, he had both John Olerud and Shawn Green come up under him. His handling of both was frustrating at times, with Olerud often platooned as a young player, and Green treated similarly when he came up in 1995. But when Gaston took over last summer, he was handed Lind and played him every day, and has continued to do so this year. Given Snider, he’s protected him against left-handers so far, which is mildly discouraging, but considering Snider’s age and inexperience, not indefensible.

Gaston appears to have learned from past experience, and changed his approach. That may be real.

Finally, there’s the schedule. You can’t hold this against the Jays, who are playing the hand they’ve been dealt, but they have benefited from a schedule that has thus far included none of their three AL East rivals, teams that may be the three best in the league. The Jays have played every team in the AL Central, as well as the A’s and Rangers in the West. They have illustrated a point I think every analyst would agree with: if you put the Jays in any other division, they would be at worst a contender, and often a favorite. The pessimism about their chances this year stems in no small part from their having to play perhaps the toughest schedule in baseball. They haven’t gotten into that yet, and in fact, they won’t see the Red Sox, Yankees, or Rays for another two weeks. They play every AL team other than the Mariners before seeing any of those three, and in fact, the Jays don’t play the Rays at all until June 29. (In a whack-job of a schedule, the Jays play just nine of their first 78 games against the big three, then get them 42 times in their next 71 contests.)

Until we see the Jays tested in the division, we can’t consider them real. Their pitching, especially the bullpen, has been impressive in light of their losses, their young left-handed hitters have bolstered the offense, they have played strong defense, and Gaston seems to have learned from some mistakes he made in the past. However, with so much of their success built on overperformance by mediocre veterans and a soft schedule, skepticism is warranted It will probably be warranted, given the schedule, until well after the All-Star break.