You were experimenting with sports betting and found yourself profitable with your strategy. However, you can’t raise a bigger bankroll to generate larger profits. Then there’s this one guy who believes in you and is willing to lend you money, of course, with interest, almost like a loan shark rate. The question is, would you see this as an opportunity or just a trap?
Regardless how good and profitable you are in gambling, it's not advisable to take a loan just to fund your gambling activity. Because there's no specific strategy that can consistently work, it could be you're just lucky plus your knowledge about sports. But then, if you want to increase your bankroll for big gains, don't rely to other people's money. Use your own so if something didn't go according to planned, you didn't owe anybody.