The signing of Livan Hernandez was not well-received in this corner.

His combination in recent years of a climbing ERA and declining fastball velocity, it was stated here quite emphatically, made him a “lose-lose” proposition for the Twins.

But here we are, 35 games into the Twins season and more than 50 innings into Hernandez’s workload, and the man is 5-1 with a 3.83 ERA.

Which raises the question: Is this legit, or is it a mirage?

Almost everything in his numbers suggests that he is indeed more effective than he was last season.

The one thing I most want to know when assessing a pitcher, however, is still going downhill for him: His strikeout rate, a subpar 4 per nine innings last season, has gotten even worse (3.5 K/9) this year.

The rest of his indicator numbers are improved from 2007:

n His walk to strikeout ratio (10 walks, 20 strikeouts) is far superior to last season’s (79-90).

n His walks per nine innings has been almost half last season’s. So far he’s walked 1.7 men per nine innings; last year it was slightly more than 3 walks per nine.

n Whereas in the past he was a pronounced flyball pitcher, this season he’s been an emphatic groundball pitcher. He’s averaging 15 groundballs per nine innings this season, 12.4 last season; his flyballs have dropped from 12.5 to 11.1.

Improving may not be the same thing as good. Two different methods of distilling a pitcher’s component stats conclude that Hernandez’s 3.83 ERA is a mirage, that it ought to be about a full run higher. That would put it in the range of his performance with Arizona last season, a performance that almost ended his major league career.

To be sure, his numbers are badly hurt by one cesspool of a start — April 27 vs. Texas, when he gave up nine hits and seven earned runs in less than three innings. In his other seven starts, he’s averaged seven innings an outing with an ERA of 2.75.

But that game underlines the fundamental problem for a pitcher with an 84 mph fastball: He has little margin for error.

Of the 51.2 innings he’s worked so far — a fraction of the 200-plus innings the Twins expect from him — he appears to have reinvented himself. He’s nibbling less, relying on a sinking fastball and changes of speed, using far fewer pitchers to get through innings. He appears, in short, to have brought into the basic Twins pitching philosophy.

If his current level of performance proves to be an illusion, so will the Twins’ dream of remaining a divisional contender this season.