The patented lower body shake, the diving changeup and the elaborate handshakes. Who has been key to the Mets last 4 seasons? Johan Santana.When fans think of Johan Santana they should think of a warrior, a player the Mets fans have been lucky to watch every five days. Santana hasn’t gotten a Cy Young Award nor made a playoff appearance while with the Mets, however he has pitched well enough to earn both, and has been the Mets' best and most consistent player.Santana has been the silent leader of the Mets over the past 4 years. He is what fans wish every ballplayer could be, but he’s one of a kind. He hasn’t racked up wins thanks to a lackluster offense and a leaky bullpen. The wins stat isn’t indicative of how great he has been. Over his last four seasons he has had a 2.84 ERA, 1.176 WHIP and a 15.7 WAR which includes a 7.1 WAR in 2008.Fans and experts alike often question trading young players for veteran talent and giving aging pitchers long contracts, but the Mets have done both and it has worked out. The Mets have made their fair share of bad trades over the years and have handed out more than enough bad contracts recently. The Santana trade and subsequent contract was neither. He was given a 6 year/$137.5M contract, after the Mets traded Carlos Gomez, Phil Humber, Deolis Guerra and Kevin Mulvey for him. None of the prospects have had much success, besides some flashy defensive plays out of Gomez and a perfect game from Humber.This column may be overstating his value, but remember back to September 27, 2008. The Mets playoff hopes were on the brink, and the gem Santana pitched versus the Florida Marlins. He performed like a true ace and if the Mets had a better supporting cast, Santana would be giving that kind of performance every year.Fans and analysts didn’t expect much from Santana this season, coming off a major elbow injury, up until now he has exceeded expectations. Santana has pitched to a 2.61 ERA while posting a 1.194 WHIP and a shocking 9.9 SO/9. These statistics are Santana in his prime numbers while coming off an injury that has still not allowed Chien-Ming Wang to return to the Big Leagues.The only question fans should have had coming into this season was the injury issue. No matter his lowered fastball velocity or lack of a third pitch, Santana will find a way to get the job done. He looks as good now as when he started wearing the Mets uniform and has spearheaded an exciting beginning to the season.There is no guarantee Santana will stay healthy and productive. If he doesn’t his time may be overshadowed by the large contract. Hopefully Mets fans recognize will his contributions even on a bad team for many years. However, with any luck he will continue to pitch to his current level and continue to be an integral part of the next Mets payoff team in the upcoming years.