If the strategy needs to be changed, especially repeatedly, it means that none of these strategies are working. This is because there is no strategy that can manage random events. After all, then random events would cease to be random. So it's useless to look for a winning gambling strategy based on luck. A gambler's strategy may be to manage the bankroll in order to gamble responsibly. However, in some games where skill is required, or in sports betting, different strategies can be successful.
There are strategies that can only work for a short amount of time and there are some that doesn't work anymore due to some change Eg in the market, or teams, players, etc... , to relate more in betting. To frequently change a strategy is also a kind of strategy. I think that managing a bankroll or risk management in other words is not a literal strategy. A true strategy is like a martingale. It is when you increase your bet amount after losing, in case you didn't know it yet. In sports betting, we usually need to analyse to win and I think analysing is not a kind of strategy too. Strategy in sports betting would be something like doing an arbitrage bet.