collect recent match history's apm data to report player's calculated MMR

def apmRecent(self, maxMatches=c.RECENT_MATCHES, **criteria):
        """collect recent match history's apm data to report player's calculated MMR"""
        if not self.matches: return 0 # no apm information without match history
        #try:        maxMatches = criteria["maxMatches"]
        #except:     maxMatches = c.RECENT_MATCHES
        apms = [m.apm(self) for m in self.recentMatches(maxMatches=maxMatches, **criteria)]
        return sum(apms) / len(apms)