THEME:   ways to lose at tic tac toe found in phrases   
GOOD ONES:     Three-letter combinations {& theme}   TIC TAC TOE LOSERS   
Rusty, the Iron Man?   SUPER HERO OXYMORON   
Us opponents   THEM [I first read it U.S.]   
Crest letters   ADA [dentist's union on toothpaste tube]   
Skilled pitchers   AD MEN [advertising pros]   
Nasty race tactic   SMEAR [I thought athletics]      
BTW:   Civil War nickname   ABE [yes, but it was pre-war so the clue is misleading --- and if that's the point, it isn't terribly clever]      
Tokugawa shogunate seat of power   EDO [so glad the shogunate was delineated or I would've been stumped 

   ]   
Old-fashioned show of affection: Abbr.   LTR [perhaps the worst clue in history on two levels: love letters are not old-fashioned, and a letter can be on any topic in the universe]      
"All ___": 1984 film   OF ME [never heard of the movie, but it is the name of a great old standard pop song]      
London forecasts   FOGS [Really, when would a forecaster use 
fog in the plural?  But steam FOGS a mirror --- more than I can say for …]      
RATING:    
 
  
 
Three grins = Loved it; Two grins = Enjoyed it; One grin = A bit bland for my taste; One teardrop = Not much fun