I have considered whether I am also overfocused on pre race horse markets too. But the problem is I haven't yet found comfort, enough, in any other sports markets for trading.
Football seems either stodgy (doesn't move) or insider (moves when you have no clue why). When I say insider it's likely stuff like team news I am getting later than the market knows (not fixed games).
Tennis I struggle to play it - don't know why, maybe miss the trading secrets or something, though I know the game fairly well away from trading it.
Similar to Tennis - snooker.
There are others of course, but many sports are very thin for trading as a further concern - so I keep ending up relying on horse markets mostly pre race. I still do ok, but I'd like to do better than ok, if there really was a sports market I could find to beat horses.