I would definitely exclude bets with a low chance of winning, I include lotteries and slots in this category. Actually, I haven't played these games for a long time because I just don't see the point. Some players just like slots because they are attracted by the beautiful picture and they believe in their luck, but for me it is almost a useless game. Bets are where we can control our choice, and tennis is not the only good choice, especially since it is not the most popular choice for players, you can bet on football but choose the total, or both teams will score or not, where there are only two possible outcomes.
Lotteries and slots are not the same level. To be fair I would definitely say sports is definitely better outcome, it's a better way to gamble and that would definitely what I would go with as well. But, just because that's my option too, doesn't mean that we are going to make a profit from that neither, we could make a loss if we pick the wrong player or wrong team and I have been gambling for 20+ years now and I can say that it is not really that easy, thankfully I am not doing it to make money, I put some aside every month and gamble with it and just enjoy life, not really looking to profit, but to have fun, I would love to make profit of course and did so a few times of course in this many years, but that doesn't mean that's my goal.
Lotteries and slots are not the same because lotteries have very low chance of return, only one person wins, whereas when we are talking about how to get a better return, slots at least have a small chance to make some return.