More than 40 percent of the yards allowed in every game this season have come on just a handful of gains. View the original article to see embedded media. NASHVILLE – ‘X’ marks the trouble spot for the Tennessee Titans defense. Explosive plays – gains of 20 yards or more – have been a consistent problem through the first weeks of the season. Players and coaches typically shorten that to “X plays” when discussing them, which they have done often in recent days. Tennessee (1-2) enters Sunday’s matchup with Indianapolis (1-1-1) as one of seven teams that has allowed an…