Essentially you are simply taking advantage of different competitive prices that different bookies may offer at the same time. You bet x% of your balance on one outcome and x% of your balance on another - if you win either of these outcomes then you are guaranteed to win a fixed percentage of profit. It's basically +EV gambling. But right now these odds are quite hard to find.
you will have no chance to lose with this arbitrage betting , as you bet on both sides ,
more than just a safe method actually , you just need to have a wide network ,
you need more than 1 sportsbetting account, it is not big deal i can say yes this is the safe methodin sportsbetting.
Many gamblers do play for fun but people should be careful not to waste time on thinking that they can also make a living out of gambling. It should be done for fun purpose. As far as a safe method is concerned, the word safe never comes in gambling simply because gambling = taking risk.
If you are not willing to take risk you can never make profit from gambling and hence there is no safe method to gambling.