[ATTACH=CONFIG]837[/ATTACH]I have stated for some time that I believe Francisco Liriano’s greatest impediment to success is his erratic mechanics. One can argue that he may be struggling mentally but that would be a chicken-and-egg argument – is he getting down on himself because his inconsistent delivery or is his delivery out of whack because he is in his own head? Either way, getting him back to a consistent base in his mechanics would likely alleviate the mental side of his game.

However, Liriano’s second biggest barrier to success – or perhaps issue 1B – is his inability to retire right-handed batters regularly.

On Tuesday night, he made strides towards improving in both areas.

Last month, I highlighted Liriano’s delivery issues in that he was failing to remain over his front leg and, far too often, pulling off to the third base side. This wreaked havoc on his ability to control his pitches, particularly his two-seam fastball which ran too far to the pitcher’s hand side of the zone and into the left handed batter’s box. From Angels Stadium’s off-set center field camera, we were not able to get a clear view of whether or not he remained over his front leg but FSN analyst Roy Smalley raved about how he was “stacked” better, which was essentially the crux of my analysis.

Two things jump out from the Pitch F/X data which may confirm Smalley’s assessment: His fastball location was significantly better, throwing it for a strike a season-high 63% of time, and his slider was much crisper, getting a swing-and-miss 25% of the time, also a season-high.

The latter stat, his slider’s performance, also carries into addressing Liriano’s pitching issue 1B.

Retiring righties is a serious matter for Liriano as opposing managers have figured out that he struggles mightily against them. Prior to last night’s game, managers have allowed Liriano the platoon advantage in just 15% of his match-ups, the second-lowest behind Baltimore’s Brian Matusz. What’s more is after the Angels slotted all right-handed hitters to face him on Tuesday night, Liriano is likely to move ahead of Matusz as the pitcher with the least amount of advantageous match-ups.

Liriano had become all too enamored with his changeup when facing right-handed opponents. Through his first four starts he would throw his change to righties as 25% of his pitch mix. This was not too far off his pace from the 2011 season in which he threw righties changeups 26% of his pitch distribution. However, so far into the 2012 season, the old standard of leaning on his changeup was not producing results – after all, his .474 weighted On Base Average (wOBA) against right-handed batters was a baseball-high and he had walked 10 and struck out 10.

Liriano took steps to remedy his right-handed problem on Tuesday by easing up on the slow stuff and exchanging it for more sliders.

In his first four starts, Liriano threw at least 13 changeups, maxing out at 25 against the Rays in his most recent start. In Anaheim, Liriano deployed just three changes to an Angels lineup featuring all right-handed batters. (Unfortunately, one wound up a Torii Hunter home run.) Instead, the Twins erratic lefty mixed in more fastballs and sliders. Tuesday night’s pitch distribution was much more consistent with his 2010 methods in which he would throw 40% fastballs and 30% sliders to righties rather than the 47% fastballs and 25% changeups he was throwing prior to the start this year.

And it was not just that he threw sliders, it was that he had success with sliders.

Compared to the rest of the year, Liriano’s slider has been far from the devastating whiff machine it had been in 2010. That year, he missed bats at the rate of 23%. Even last year he was getting hitters to miss at 21% of his sliders. This year, it had dropped to 15%.

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Liriano went to work attempting to improve that number by getting swing-and-misses on seven of his 28 thrown, his best rate of the season thus far. Part of what made his slider effective on Tuesday was regaining his mechanical base as well as being able to locate his fastball for a strike.

Following the game, he sounded satisfied in his overall performance in spite of shouldering the loss:

"The result wasn’t what I wanted. I made some better pitches than the last time. Feel more consistent with my slider.”

Don’t misunderstand: Liriano has a long road back to becoming a contributing member of the Twins rotation; however, Tuesday’s start should be viewed as a positive step towards turning things around.