For a span of five seasons, Tim Lincecum appeared to be on a path to become the greatest San Francisco Giants pitcher of all time. He’d won the Cy Young Award in two consecutive seasons, led all of MLB in strikeouts for three, and pitched the Giants to their first World Series title in San Francisco history. He was on top of the baseball world, and became one of the most celebrated players in the sport. Then, even more quickly than he'd ascended, he suddenly lost it all. For three seasons now, the Giants have held the dream of Lincecum working through his struggles and recapturing his dominant form, but heading into 2015, that dream needs to be given up.

When a pitcher of Lincecum’s caliber suddenly loses his ability to remain elite, it's very hard to accept. Some retain certain aspects of their former dominant selves, but Lincecum's case is extraordinary. Seldom, if ever, has there been a fall of an elite pitcher that has been so fast and so complete. Unfortunately for the Giants, there aren't any rays of hope that he can become even a serviceable starter again, let alone return to his Big Time Timmy Jim days.

Tim Lincecum IP K/9 BB/9 HR/9 BABIP HR/FB ERA FIP xFIP SIERA fWAR 2008 227 10.51 3.33 0.44 .304 5.6% 2.62 2.62 3.13 3.17 7.1 2009 225.1 10.42 2.72 0.40 .282 5.5% 2.48 2.34 2.83 2.91 7.5 2010 212.1 9.79 3.22 0.76 .310 9.9% 3.43 3.15 3.09 3.19 4.2 2011 217 9.12 3.57 0.62 .281 8.0% 2.74 3.17 3.36 3.45 3.6 2012 186 9.19 4.35 1.11 .309 14.6% 5.18 4.18 3.82 4.05 0.8 2013 197.2 8.79 3.46 0.96 .300 12.1% 4.37 3.74 3.56 3.68 1.5 2014 155.2 7.75 3.64 1.10 .299 13.9% 4.74 4.31 3.81 3.95 -0.2

While his peripherals suggest that he’s been somewhat unlucky over the past three seasons, they’re mostly in agreement that Lincecum just isn’t good anymore. The lower xFIPs can be explained by his unusually high HR/FB ratio, and apart from 2013, both his FIP and SIERA have been just around average. His strikeout rates have decreased dramatically while his innings pitched have plummeted, and for the first time in his career, he produced a negative fWAR.

The most notable aspect of his decline has undoubtedly been the loss of his fastball. In 2008, the first of his Cy Young seasons, Lincecum averaged 94 MPH; that number fell to 89.6 in 2014. No longer can he reach back for that extra velocity to put a hitter away, and there's no evidence to suggest a rebound. Compounding Lincecum's issues is the fact that as his fastball has slowed, his splitter's (sometimes referred to as his changeup) velocity has remained largely intact. When the pitch first became a weapon for him, there was a stark contrast between the two pitches, resulting in a difference of 11 MPH; however in 2014, the gap has narrowed to only 7 MPH.

The other red flag for Lincecum has been the dramatic decrease in effectiveness of his once-deadly splitter. In 2007, he saw almost 5 inches of horizontal break (the negative value signifies it moved in towards a RHB) coupled with 6 inches of vertical drop. Since then, both numbers have decayed, and in 2014, Lincecum could muster only -0.73 inches of horizontal break, and only 3 inches of vertical drop.

If the Giants didn't have any options for replacing Lincecum, then keeping him in the rotation would at least be defensible, but with Yusmeiro Petit lurking in the bullpen, that's simply not the case.

Most baseball fans were introduced to Petit when he broke Mark Buehrle’s record for consecutive batters retired late this August, but he’s been a surprising contributor with San Francisco since July of 2013.

Yusmeiro Petit IP K/9 BB/9 HR/9 BABIP HR/FB ERA FIP xFIP SIERA fWAR 2013 48 8.81 2.06 0.75 .313 6.7% 3.56 2.86 3.48 3.35 0.8 2014 117 10.23 1.69 0.92 .290 9.1% 3.69 2.78 2.84 2.51 1.7

Petit has never been a flashy pitcher, "boasting" a fastball that averaged only 88.7 MPH (slower than Lincecum's!) in 2014. Instead, he has relied on impeccable and improving control throughout his tenure in San Francisco. But there's something else going on with Petit beyond just his control. During the World Series, Eno Sarris of FanGraphs detailed one of the reasons for why Petit is seemingly so difficult to figure out. He called it the "Invisiball", and through some gifs you can see why. Petit first shows the ball near his head, then it disappears only to be shown again in a far different location. This deception is likely a strong reason for Petit's success, and was on display during his incredible relief outing in game 2 of the NLDS.

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Of his seven strikeouts, four of them came on fastballs to Wilson Ramos, Adam LaRoche, Ian Desmond, and Bryce Harper, all of whom are above average when it comes to hitting against that pitch. Yet none of those pitches reached a velocity higher than 89 MPH, adding weight to the theory that hitters simply can't pick up the ball against Petit.

The final nail in Lincecum's starting pitching coffin comes courtesy of FanGraphs’ pitch values.

2014 Pitch Values wFB wSL wCB wCH Tim Lincecum -9.7 -3.7 -2.1 -1.2 Yusmeiro Petit -3.9 8.6 3.1 4.3 Run difference +5.8 +12.3 +5.2 +5.5

While Petit didn’t fare particularly well in the fastball department overall, it was still an improvement over his counterpart. Amazingly, Lincecum didn’t manage to produce a single positive value on any of his pitches, just another indicator in a growing line of statistics that prove he doesn't deserve a rotation spot anymore.

The main argument against moving Lincecum to the bullpen full time seems to be the fact that he’s owed $18 million dollars next season, but that’s not a legitimate reason. The money that Lincecum is set to receive is a sunk cost; there’s nothing the Giants can do about it outside of finding a trade partner that’s willing to take on some of the contract. Since that seems very unlikely at this point, the best thing that the Giants can do for the 2015 season is to put Lincecum in the bullpen and give Petit a shot at the 5th spot in the rotation. He's shown the ability to be a starter, and at this point deserves a chance to claim it for an entire season.

Moving Lincecum to the bullpen isn't completely out of nowhere, either. He proved to be a big weapon during the 2012 playoffs, and there is some precedent for starters regaining velocity once making the transition to the reliever role full time. While it's impossible to know how he'd react to starting the season off as a reliever, at this point in his career it would serve both him and the Giants well to find out. He's in the final year of a massively overpaid contract (2 years for $35 million), and isn't likely to fetch any real money on the open market as a starter. However, with the recent influx of cash suddenly being thrust upon middle relievers and closers, he might be able to reinvent himself as a bullpen weapon, much like Wade Davis did in Kansas City.

Wade Davis IP K/9 BB/9 HR/9 BABIP HR/FB ERA FIP xFIP SIERA 2013 (Only as a starter) 125.1 7.68 3.88 1.08 .376 11.4% 5.67 4.28 4.17 4.3 2014 72 13.63 2.88 0 .264 0% 1.00 1.19 1.93 1.61

There's no point in letting Lincecum struggle in the rotation anymore, and with Petit willing and able to step into a starting role, the time is now to find out how each would fare. One of the many definitions of insanity is "doing the same thing over and over again and expecting different results", and while nobody seems to be quite certain who first said this, the fact is it's incredibly relevant to the Giants' situation. Lincecum has not been good for three years, while Petit has been somewhat of a savior for two; thus, for the Giants to continue to ignore the reality of what's going on would truly be insane.

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All statistics courtesy of FanGraphs and Brooks Baseball.

Matt Goldman is a Contributor for Beyond the Box Score. You can follow him on Twitter at @TheOriginalBull.