Duda playing first marks the end of a long, strange saga in which the Mets insisted Duda was a capable outfielder despite all evidence to the contrary. In 2012, Duda was the worst defensive outfielder in baseball, grading out at -20.3 by UZR and -41.3 UZR/150 when he played right field. Left field hasn't gone much better for him, as he graduated out at -11.0 UZR and -31.9 UZR/150 in 2013. For comparison's sake, Duda graded out at 0.4 UZR and 1.5 UZR/150 in his only meaningful time at first in 2011.
UZR is a very flawed statistic, but for Duda, it reflects reality. For all of his effort, Duda never possessed the range or foot speed to adequately track and catch fly balls, and he frequently had balls go over his head.
Duda's defense meant that despite providing a 101 and 118 wRC in 2012 and 2013, his fWAR in those two years combined was -1.9.
Whether it was because of Valdespin's lack of hitting or something else, the Mets have changed course and for the first time since 2011, Duda will have the chance to provide above average value.