Could just be a coincidence, but I'm starting to notice a pattern in my H2H matchmaking:
Games 1-3: Players with good teams but beatable strategies. I usually win all of these.
Game 4: Not always game 4, could also be at 3 or 2. Usually in this game series range I play one "cupcake" team, aka some kid who got the game for Christmas and has 92s or lower in his top three.
Game 5+: Good team, good players. These are the players I have the most trouble with. Not only do they have a top-tier team, but they have the strategy to go along with it. It seems EA backloads my season matchmaking with all the tough opponents. Again, probably just coincidence, but I almost never face a top-tier player at the beginning of Seasons. I've won a little less than half of these matchups, but usually if I lose one game to the players with just good teams this is the point that I get eliminated before the playoffs.
It was exactly that way when I played H2H this morning: Three decent opponents, one terrible opponent, and then a backload of elite players that stopped me from getting the fifth win I needed.