Likelihood of winning the blocks event
If you assume that the potion placement is random, here is the probability of winning at each potion number:
• 11: 0.000006% (1/16689036)
• 12: 0.000072% (1/1390753)
• 13: 0.000467% (1/213962)
• 14: 0.002181% (1/45849)
• 15: 0.008179% (5/61132)
• 16: 0.026170% (1250/4776387)
• 17: 0.074115% (1180/1592129)
• 18: 0.190311% (3030/1592129)
• 19: 0.450497% (14345/3184258)
• 20: 0.994479% (76905/7733198)
• 21: 2.063407% (7721/374187)
• 22: 4.043946% (173/4278)
• 23: 7.504292% (1661/22134)
• 24: 13.186645% (550181/4172259)
• 25: 21.893416% (913450/4172259)
• 26: 34.188243% (2413945/7060746)
• 27: 49.877272% (2347805/4707164)
• 28: 67.418938% (113340/168113)
• 29: 83.750216% (4855/5797)
• 30: 95.246310% (38650/40579)
• 31: 100.000000% (1)
Notice how skewed the odds are? It’s only “unlucky” around potion 28 or 29.