Round 4 Sam will cast Shocking Grasp and attack the thing again, if it drops he should be able to attack the other one with his 15' reach with whatever attacks are left
To Hit - 1d20 + 18 ⇒ (15) + 18 = 33
Damage - 1d6 + 11 + 10 + 2d6 + 2d6 + 10d6 ⇒ (3) + 11 + 10 + (6, 4) + (4, 2) + (2, 6, 2, 1, 3, 6, 1, 4, 1, 2) = 68
Confirm Crit - 1d20 + 18 ⇒ (8) + 18 = 26
Total Damage - 1d6 + 11 + 10d6 + 68 ⇒ (4) + 11 + (5, 4, 1, 5, 5, 4, 2, 6, 4, 2) + 68 = 121
To Hit - 1d20 + 18 ⇒ (2) + 18 = 20
Damage - 1d6 + 11 + 10 + 2d6 + 2d6 ⇒ (5) + 11 + 10 + (3, 3) + (5, 6) = 43
To Hit - 1d20 + 18 ⇒ (12) + 18 = 30
Damage - 1d6 + 11 + 10 + 2d6 + 2d6 ⇒ (2) + 11 + 10 + (5, 1) + (4, 4) = 37
To Hit - 1d20 + 11 ⇒ (17) + 11 = 28
Damage - 1d6 + 11 + 10 + 2d6 + 2d6 ⇒ (1) + 11 + 10 + (3, 2) + (6, 6) = 39
Confirm Crit - 1d20 + 11 ⇒ (20) + 11 = 31
Total Damage - 1d6 + 11 + 39 ⇒ (6) + 11 + 39 = 56