A steady dose of Aaron Cook was all the Diamondbacks needed to break a 10-game losing streak. Arizona defeated the Rockies 7-6 on a walk-off single from Brian Roberts.

While many would blame the bullpen for not shutting the door on Arizona (they gave up four of the seven runs), the loss falls on the shoulders of the Rockies’ former ace.
On Friday night at Chase Field, Cook was given a 1-0 lead after Carlos Gonzalez led off the game with a home run. For a team that has lost 10 straight, including four in a row via the walk off, and also including two straight extra inning games in a row in which the offense put up zero runs, it must have felt like it was happening all over again.
Instead, Aaron Cook decided to continue working on his secondary pitches, and immediately gave away the lead. The right-hander made it to the big leagues using little deception. He throws the sinker when everyone in the park knows its coming, yet gets ground ball outs.
As has been par for the course in 2010, Cook ditched the sinker early. The second pitch of the night for Cook was a curveball. Cook gave up a base hit to Kelly Johnson before giving up an absolute bullet of a home run to Justin Upton.
The problem for Cook is that he falls apart when the offense gives him a lead. In his 11 starts so far in 2010, the redhead has been given a lead by the Rockies offense in eight of them.
Cook’s 2010 debut in Milwaukee on April 7 was a microcosm of his season to date. After being staked to a 3-0 lead, Cook put the sinker in his back pocket and started playing around with his curveball and four-seamed fastball.
At Washington on April 19, Cook was given a 2-0 lead and he proceeded to give that one away, too. In just three innings of work, Cook gave up five runs on seven hits.
In Kansas City 12 days ago, Cook matched up with Zach Grienke and was given a 9-0 lead heading into the fifth inning. He was unable to pitch the required five innings to pick up the win.
The club held on to win the game 11-7, but Cook let the Royals back into the game. He gave up four runs in the fifth inning, forcing manager Jim Tracy to give him the hook before getting the final out in the fifth inning.
On May 12 against the Philadelphia Phillies and Roy Halladay, the offense figured out Halladay to the tune of three runs.
Instead of putting his foot down, the Rockies pitcher gave Halladay another chance, allowing the Phillies offense to tie the game. In the end, Miguel Olivo ended up winning the game in extra innings, but Cook kept Philadelphia in it.
On Friday night, Cook did enough to keep his team in the game. After he departed, the bullpen faltered. While much of the blame goes on the bullpen, it was Cook who inspired confidence in a bumbling Diamondback offense.
A pitcher needs to know who he is facing when he takes the mound. Cook needed to know that the D-Backs had been struggling to score runs. Obviously, Cook is not trying to give up runs, but when a team that is struggling sees themselves start to fight back, it inspires confidence.
That is exactly what happened Friday. Suddenly a desperate Arizona lineup saw the light at the end of the tunnel.
Instead of feeling like they were going to be owned by a sinkerball pitcher who was going to frustrate them even more, they immediately were gifted a way to break out of their slump by Cook.
Whether Cook has lost confidence in his sinker or if he wants to prove he can be a curveball pitcher remains unclear. The fact is however, that Cook continues to dabble with the off speed stuff.
Until Cook decides to quit trying to reinvent himself, he is going to continue to struggle. If he ditches the curveball and throws the sinker 80 percent of the time, he will have a better chance of figuring out a way to get back to what got him to the All-Star game in 2008.

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