BetVictor's "Tennis Acca Insurance" offers a safety net for bettors who place accumulator bets on tennis matches. If one selection in the accumulator loses, bettors are eligible for a refund of their stake as a free bet, typically up to a specified limit. To qualify for this insurance, bettors need to place a minimum of three selections on their accumulator bet, all of which must be on tennis markets. Additionally, the bet must be placed at the minimum odds stipulated by the promotion. It's essential for bettors to check the specific terms and conditions on the BetVictor website for any updates or particular requirements related to this promotion.