Head to head
Simon Kellum vs Declan Mangan-Lamb
Two careers, 54 shared rounds, one running count. Everything below comes from the official results the two of them posted in the same rounds of the same competitions.
Simon Kellum (United States) and Declan Mangan-Lamb (Ireland) have met in 54 rounds across 5 competitions since 2023. Counting every round where both finished with a result, Simon Kellum leads Declan Mangan-Lamb: 49 finishes in front to 5.
On personal bests the split is just as plain: across 15 shared events, Simon Kellum holds the faster single in 15, Declan Mangan-Lamb in 0.
Personal bests, side by side
faster single in bold| Event | Simon Kellum single | average | Declan Mangan-Lamb single | average |
|---|---|---|---|---|
| 3×3 | 4.91 | 7.06 | 7.31 | 8.96 |
| 2×2 | 0.71 | 1.44 | 0.91 | 2.33 |
| 4×4 | 29.24 | 35.27 | 33.50 | 37.92 |
| 5×5 | 55.69 | 1:04.66 | 1:07.78 | 1:13.18 |
| 6×6 | 1:53.03 | 2:06.17 | 2:19.34 | 2:35.94 |
| 7×7 | 2:57.72 | 3:15.06 | 4:04.72 | 4:21.61 |
| 3×3 blindfolded | 39.08 | 1:02.97 | 1:33.32 | — |
| 3×3 Fewest Moves | 19 moves | 20.67 | 29 moves | 37.00 |
| 3×3 one-handed | 8.49 | 11.90 | 15.91 | 21.94 |
| Clock | 4.00 | 4.88 | 5.39 | 6.60 |
| Megaminx | 39.37 | 45.94 | 45.50 | 51.90 |
| Pyraminx | 0.73 | 1.53 | 1.91 | 3.69 |
| Skewb | 0.85 | 1.71 | 0.95 | 2.21 |
| Square-1 | 6.65 | 10.13 | 16.96 | 23.50 |
| 3×3 Multi-Blind | 10 of 12 cubes · 56:45 | — | 3 of 4 cubes · 24:03 | — |
Year by year
every meeting, 54 rounds in allRecent meetings
newest first · averages where the round ranked on one, singles otherwise| Year | Competition | Event | Round | Simon Kellum | Declan Mangan-Lamb | ahead |
|---|---|---|---|---|---|---|
| 2026 | Rubik's WCA North American Championship 2026 | 2×2 | First round | 2.36 | 3.38 | Simon Kellum |
| 2026 | Rubik's WCA North American Championship 2026 | 3×3 | Second round | 7.60 | 10.11 | Simon Kellum |
| 2026 | Rubik's WCA North American Championship 2026 | 3×3 | First round | 8.63 | 10.06 | Simon Kellum |
| 2026 | Rubik's WCA North American Championship 2026 | 3×3 one-handed | First round | 12.94 | 23.50 | Simon Kellum |
| 2026 | Rubik's WCA North American Championship 2026 | 4×4 | First round | 36.71 | 41.09 | Simon Kellum |
| 2026 | Rubik's WCA North American Championship 2026 | Megaminx | First round | 55.39 | 57.23 | Simon Kellum |
| 2026 | Rubik's WCA North American Championship 2026 | Pyraminx | First round | 2.10 | 5.22 | Simon Kellum |
| 2026 | Rubik's WCA North American Championship 2026 | Skewb | First round | 2.89 | 2.88 | Declan Mangan-Lamb |
| 2026 | Rubik's WCA North American Championship 2026 | Skewb | Final | 3.09 | 3.40 | Simon Kellum |
| 2026 | Rubik's WCA North American Championship 2026 | Skewb | Second round | 2.62 | 2.21 | Declan Mangan-Lamb |
| 2025 | CubingUSA Great Lakes Championship 2025 | 2×2 | First round | 1.59 | 4.40 | Simon Kellum |
| 2025 | CubingUSA Great Lakes Championship 2025 | 2×2 | Second round | 1.46 | 4.30 | Simon Kellum |
| 2025 | CubingUSA Great Lakes Championship 2025 | 3×3 | First round | 9.66 | 10.58 | Simon Kellum |
| 2025 | CubingUSA Great Lakes Championship 2025 | 3×3 | Second round | 9.51 | 12.22 | Simon Kellum |
Full careers: Simon Kellum · Declan Mangan-Lamb. A meeting is a round of one event at one competition where both finished with a counted result. Who finished ahead follows official placing in the round: rounds played to an average are won on the average, best-of rounds on the single.