What is Chinese Checkers with 15 pieces?
With only two players, two of the six points of the star face each other and the other four stay empty, so the board has room for bigger armies. In this version each player starts with 15 pieces instead of 10. The four rows of the point hold the usual 10 pieces, and a fifth row of five pieces stands along the edge of the central hexagon, directly in front of the point.
Everything else is the standard game. You move one piece per turn, either one step to an empty neighbouring hole or a chain of hops over single pieces, and the first player to fill the opposite point wins. That point now counts its fifth row too: all 15 holes must hold your pieces.
The extra row changes the opening. The two armies start closer together, with fewer empty rows between them, so they meet and start using each other's pieces as stepping stones sooner. Each side also has half as many pieces again to bring home, which makes the game longer and the final packing of the goal harder.
Rule changes
| Rule | Standard Chinese Checkers | Chinese Checkers with 15 pieces |
|---|---|---|
| Pieces each | Standard Chinese Checkers10. | Chinese Checkers with 15 pieces15. |
| Starting position | Standard Chinese CheckersA triangle of four rows (1, 2, 3 and 4 holes) filling one point of the star. | Chinese Checkers with 15 piecesA triangle of five rows: the four rows of the point plus a row of five holes on the edge of the central hexagon in front of it. |
| Players | Standard Chinese Checkers2, 3, 4, 5 or 6. | Chinese Checkers with 15 pieces2 only. With more players, neighbouring five-row triangles would meet at the corners of the hexagon. |
| How to win | Standard Chinese CheckersFill the four rows of the opposite point with your 10 pieces. | Chinese Checkers with 15 piecesFill the opposite five-row triangle, the row in front of the point included, with your 15 pieces. A piece inside it may move within it but never leave it, as in the standard game. |
| Shortest possible game | Standard Chinese Checkers30 moves in all (15 by each player), as computer search has shown. | Chinese Checkers with 15 pieces36 moves in all, by the same computer search. |
History
Two players can share the star in several ways: each may control one, two or three armies. When each plays a single army, the pieces usually race into the opponent's starting point, and the number of pieces per side is usually raised from 10 to 15. David Parlett's The Oxford History of Board Games (1999) notes that two players may use 15 pieces each.
Both army sizes have been studied as puzzles. In 1979 David Fabian found a complete two-player game with 10 pieces each in 30 moves, which Martin Gardner reported, and he also found a 38-move game with 15 pieces each. In a paper published in 2009, George I. Bell used computer search to prove that 30 moves is the shortest possible with 10 pieces, and that with 15 pieces the shortest possible game is 36 moves, two fewer than Fabian's.