What Does “Under 21” Mean in Tennis Betting?
In tennis totals betting, “Under 21” refers to a wager that the total number of games played in a match will be fewer than 21.
Formula:
Total Games = Games played in Set 1 + Set 2 (and Set 3 if applicable)
You win the bet if:
Total Games < 21
Examples to Understand
Example 1 (Bet Wins):
- Final Score: 6-3, 6-4
- Total Games = 6+3 + 6+4 = 19
Bet Wins (19 < 21)
Example 2 (Bet Loses):
- Final Score: 6-4, 5-7
- Total Games = 6+4 + 5+7 = 22
Bet Loses (22 > 21)
Example 3 (Bet Pushes/Draw – only in “Under 21.0” line):
- Final Score: 7-6, 6-7
- Total Games = 13 + 13 = 26
Bet Loses
Important Notes
- This bet is only about total games, not sets or the match winner.
- Works for best-of-3 matches (most ATP/WTA matches).
- In a straight-sets (2-0) win, this bet is more likely to hit.
- If the line is Under 21.5, a total of 21 games is a win.
- If it’s Under 21.0, exactly 21 is a push (stake refunded).
Betting Tips for Under 21 in Tennis
1. Target Mismatched Matches
Look for matches where a clear favorite is expected to dominate (e.g., World No. 5 vs World No. 100). These are likely to end quickly.
2. Clay Courts Are Riskier
Clay courts often produce longer rallies and more breaks, which may lead to more games. Prefer fast surfaces(hard/grass) for Under bets.
3. Check Head-to-Head History
If past matches between players ended in quick straight sets, it’s a good sign.
4. Beware of Big Servers
Players with strong serves (e.g., Isner, Raonic) often go to tie-breaks, increasing total games. Avoid betting Under when they are involved.
5. Use Live Betting
If one player dominates early, you can live bet on “Under” at better odds as the total drops.
Ideal Match Scenario for Under 21
- One strong player (Top 10) vs a weak qualifier
- Fast surface
- Dominant head-to-head history
- No big servers
- Straight-set outcome expected (e.g., 6-2, 6-3)
Would you like me to provide today’s matches with good Under 21 potential or track upcoming tournaments for this strategy?