Can these surprising teams stay hot all season?

Who would have thought it?

The Cincinnati Reds, Arizona Diamondbacks and Los Angeles Angels averaged 70 wins between them in 2016, but they’re a combined 20-8 so far this season.

The hot starts have brought considerable optimism to their fan bases. But we’re not necessarily sure that’s fully warranted.

Cincinnati Reds

The Reds have outscored opponents 48-23 in their nine games this season, an impressive beginning to the season, with a 7-2 record that matches their 1990 start, when they won the World Series. And there may even be a feeling of “Wait until Joey Votto gets going” given that their star isn’t even hitting .200 yet.

But there’s a lot in this win-loss record that appears abberational. Eugenio Suarez is hitting .429. He wasn’t even a .260 career hitter prior to this season. Similar cases could be made for Zack Cozart (.417), Tucker Barnhart (.333) and Billy Hamilton (.306). None of them ever hit better than .260 in a full season.

The excitement comes in the form of the youngsters in the starting rotation, such as quick-starting rookie Amir Garrett, who has a 1.42 ERA in two starts. But they’re still asking a lot out of the likes of veterans Scott Feldman and Bronson Arroyo, the latter of whom pitches on Thursday. The bullpen has a 1.23 ERA another number that likely won’t last, though it should be massively better than the group that posted a 5.10 ERA, unless injuries get in the way.

The projection systems still haven’t bought in. Fangraphs pegs the Reds to go 72-90, tied for the fifth-worst record in baseball.

Arizona Diamondbacks

Of these three teams, the Diamondbacks may have the best case for legitimacy, given the track records of some of their most notable players -- Paul Goldschmidt, Zack Greinke and A.J. Pollock.

They’ve also taken to a strategy of sacrificing a little offense in their primary catcher, Jeff Mathis, in return for better defensive work. Mathis ranks third among catchers in getting his pitchers extra strikes, nearly on par with the standard-setter at the position, Buster Posey. And Mathis has hit too -- but given that he entered the year with the lowest OPS in baseball, that probably isn’t going to last.

The question marks come largely from the starting rotation beyond Greinke (of whom there are fastball velocity concerns). Taijuan Walker has a history of inconsistency (two seasons with ERAs of 4 or higher). Patrick Corbin needs to show he can bounce back. Shelby Miller is coming off a 6.15 ERA and largely diminished velocity. And Robbie Ray may be better than his 4.90 ERA showed last season, but he has never had an ERA below 3.50.

The prediction systems still sit somewhere in the middle with this team. Fangraphs has them at 80-82.

Los Angeles Angels

There has been a bullishness to the Angels, a team has three wins when trailing entering the ninth inning.

But let’s remember: Last season, the average team won three games when trailing in the ninth inning all season. So this isn’t something that they can bank on as a trait that will hold consistent throughout the season.

Positivity comes from Mike Trout and the potential to maintain the post-1.000 OPS level he’s at right now. Any team with a player capable of a 10-WAR season is always going to have a chance, just because that player is so much more valuable than everyone else.

But concerns are visible, particularly in the starting rotation, where there’s little depth and already one man down (their likely ace, Garrett Richards). Their starters have a combined ERA of 5.67 and rank last in the majors in FIP due to because they don’t strike hitters out (26th in strikeouts per nine innings), they walk a lot of hitters (17th in walks per 9) and allow a lot of home runs (last in home runs per nine).

So though the projections may be for 85 to 86 wins, that’s admittedly a number on highly shaky ground.