The UTG is based off a simple measure, the Kendall Unit of Grit(KUG) which is the amount of grit that Jason Kendall emits while at rest, ie mowing the yard, getting his hair cut or just normal everyday stuff.  He is the basis because his grit ranking is the highest in recorded history for at rest measurements.  There are rumors that their is another being that can emit more grit, the Ecksteinosaurus, but this has never been verified.  The closest we have ever come to the Eckstenosaurus in captivity is the Davidecksteinosaurus which is its smaller cousin.  While impressive in its own right, the Davidecksteinosaurus is only capable of about .85 KUGs.  It has been extrapolated that a full grown Eckstein could be capable of 1.3-1.4 KUGs, but for right now that is just idle speculation.

Some of the key factors in grit production are facial hair(but only if it's un-ironic, so Giambi gains no grit credit for that monstrosity he is sporting), crappy offense, running hard to first all the time, playing so poorly it causes  the media to make excuses for the crappy offense and looking like you're trying really hard.  To give you a thumbnail sketch of KUG, here is a list of recent players and their grit production:

Derek Jeter: 0.35 KUG-diving into stands and having the media adoration adds to the KUG rating, but being good on offense and poor on defense hurts.  KUG rating has been rising the last 12 months as one of those problems seems to be solving itself

Alex Rodriguez: (5.00)KUGs-clearly being the best player of his generation hurts his rating, the only positive movement of his KUG was his move to third to salve a teammate's hurt feelings

Jason Veritek: 0.90 KUGs-Same explanation as Jeter, but with more facial hair and alot less offense.  Lacking the existence of Jason Kendall this scale could have easily been called the VUG

Barry Bonds: A negative billion KUGs-ditto A-Rod plus surliness to everyone and the PED issues.  Gritty players don't juice, but do sign autographs for all the precious children

When under stress or pressure, a person with a positive KUG rating is capable of able to produce more grit than normal.  So during a high leverage situation it is not unheard of for the right player to increase their KUG measurement to 2 KUGs.  For an elite KUG-man, they can crank it up to 5 KUGs.  No recording of more than 5 KUGs has ever been made, but there is a growing body of work that the Tunguska Event was the result of a release of 8 KUGs.  But once again this is idle speculation and no one is able to even comprehend the event that would lead to this level of grit.

Now, all of this research is only good if it can be applied to the real world and I believe I KUG analysis can explain what is ailing two of the Brewers bullpen acquisitions.  Both Gagne and Mota made their reputations as elite closer and setup man while with the Dodgers.  Their catcher while they were at their best was one Paul Lo Duca.  Now normally a last name ending in a vowel is good for at least 0.20 KUGs, but Lo Duca defied this trend early in his career by being an ok but not great catcher and above league average hitter which left him with a paltry 0.10 KUG rating for his time with the Dodgers.  This is a barely recordable amount of grit, and it was at this time when Gagne and Mota were posting the gaudy ERA+s of 180 and better and it has been downhill since.

Mota has been a disaster for much of the time since, and it can be traced to a KUG overload.  While the Paul Lo Duca of the LA Dodgers was a low KUG emitter, by the time Mota caught up with Lo Duca in Florida and again in New York the man had become grit machine cranking out 0.60 KUGs as his skills faded and he relied on fan appreciation of his hustle and willing dupes in the media to stay in the lineup.  This clearly impacted Mota as he posted some of the lowest ERA+s of his career.

For an even sharper explanation, Eric Gagne is the classic grit intolerant player.  After his injury/PED withdrawal, he went to the Rangers where his catcher was Gerald Laird.  Laird was an up and coming prospect who struggled in his first full season in the show.  While he was offensively challenged, he didn't have the expectation of sucking nor the veterandom that promotes grit production.  He weighed in at a modest 0.20 KUG, which was not enough to interfere with Gagne's performance.  Alas, this was not to last for the full season as Gagne was dealt to the Red Sox and had to pitch to Veritek and his 0.90 KUG production.  Gagne simply could not cope with the grit storm that he was surrounded with nite in and nite out, and Veritek has never been able to control his grit output.  The trade ended predictably in disaster.

So that brings us to this year and G&M being forced to deal with the namesake of the grit scale.  Once again, we have faced disaster.  But all is not lost.  Now that we have identified what is causing the problem, we are a short distance from solving the problem.  While it is not possible for Kendall to emit less than 1 KUG, it is possible that he limit his excess grit in high leverage situations.  What we need is someway to convince Kendall that as the game gets later and the score gets closer, that the exact opposite is actually happening.  How this is achieved is beyond my abilities as a researcher, but now that the solution to our problem is exposed for the world to see I can only hope someone somewhere resolve this problem.