Four surprisingly good pitchers to add to your fantasy team

Trevor Cahill is one of two Oakland pitchers worth picking up for your fantasy team based on their recent performances. AP

As we wrap up the month of May and the first third of the MLB season, it's once again time to check in on our "Rule of Seven" to see if there might be some potentially elite starting pitchers out there who, for whatever reason, still haven't latched on to rosters in fantasy leagues.

For the uninitiated, this shortcut stat requires a pitcher to post an ERA of 3.50 or less and a K/BB of 3.50 or higher. Add those two simple stats, and you get seven, hence the name. That may not seem like a terribly high bar to achieve, but I've discovered that at any given time during the course of a baseball season, you're likely to find only about 25 or so members of this exclusive club, given an appropriate minimum number of starts.

Back in March, there was a clear tier of eight pitchers we projected as being in this elite club for 2018: Clayton Kershaw, Max Scherzer, Corey Kluber, Chris Sale, Stephen Strasburg, Noah Syndergaard, Madison Bumgarner and Carlos Carrasco.

The only thing keeping this octet from all making the list today is a spring training line drive off the hand of Bumgarner (who is just about ready to make his 2018 debut) and a somewhat sub-par month from Carrasco which bumped his ERA over the limit -- though he's only a shutout away from the bouncer letting him back inside the premises.

Also on the May membership ledger are somewhat expected options Luis Severino, Jacob deGrom, Aaron Nola, Justin Verlander, Gerrit Cole and James Paxton, along with our "with a little luck" flier Ross Stripling.

It may be too late to snare some of the other names on this list who are already on more than two-thirds of ESPN rosters: Patrick Corbin, Charlie Morton, Kyle Hendricks, Miles Mikolas, Walker Buehler and Nick Pivetta. However, here's a quick snapshot of the remaining four non-injured "Rule of Seven" options for your consideration:

Daniel Mengden, Oakland Athletics (56.5 percent rostered): While he started the season slowly with a 6.19 ERA after three starts, the mustachioed Mengden has now hurled four consecutive quality starts -- including 16 scoreless innings over his last pair of outings. While he may not whiff a ton of hitters per game, he's also yet to allow more than a single free pass in any contest.

Jeremy Hellickson, Washington Nationals (38 percent): He's pretty much been a "get in/get out" starter this season, yet to reach 95 pitches in any of his eight starts and rarely even finishing the sixth inning. Still, he has a 1.30 ERA in May, so what he lacks in volume, he's more than making up for in pure stinginess.

Trevor Cahill, Oakland Athletics (29.1 percent): The A's are a .500 team, so perhaps it's not too shocking to have a second Oakland SP on this list. Then again, Cahill went 0-1 in four May starts, despite a 1.73 ERA and a .185 BAA. His home/road splits seem to indicate only starting him at the Coliseum where he has a 0.64 ERA, compared to a 5.06 ERA elsewhere, but if those trends keep up, rostering him certainly makes a ton of sense.

Wade LeBlanc, Seattle Mariners (10.6 percent): Pressed into a starting role when Erasmo Ramirez went on the disabled list on May 1, the converted reliever has slowly stretched out to where he's giving Seattle six innings per start. They've been pretty good ones, too. Although he's yet to nail down a win this season, when he takes the mound Thursday for his sixth start of 2018, he'll bring with him a 1.71 ERA and a .214 BAA for the month.

Finally, three pitchers who failed to pitch a minimum of five starts but would have otherwise made the cutoff might be worth speculative pickups. They are Sam Gaviglio, Blaine Hardy and Elieser Hernandez.