I believe the original photograph was taken in 1911, based on Okkonen's work and the ballpark ads.
Some don't agree...
FYI... from a 2007 Legendary auction:
http://www.legendaryauctions.com/Lot...x?lotid=75975#
This would have been the season when Matty finally lost the magic, dropping to eight wins this year after 12 straight seasons as a 20-game winner. "Big Six" was still a very dangerous hurler at this stage, but after this season he was no longer the man McGraw had always relied on the most. A bit of the frustration that Mathewson must have been feeling at this point seems to come through in the stern set of his jaw and the look in his eye. The one thing we are having a bit of trouble with in this photo is the cap, which appears to be from the 1911 season, while all of the other uniform details match those of uniforms worn in 1915. (Only the bill of the cap was dark for 1915.) Perhaps Matty was trying to bring the magic back, wearing one of the caps from his salad days for luck. In any regard, this outstanding original Conlon photo is one that all Matty fans want to own. It remains in exceptional EX/MT condition, with only the most minor of surface faults. The iconic photograph comes to us from a consignor who has had direct access to the Mathewson estate and who confirms its origin with Christy's wife, Jane Mathewson.