The steps of TopSpin (pieces in ascending order)



Step 1

The first 16 pieces

When the first 16 pieces are placed,
your topspin will look like this:


No particular algorithm
Step 2

The 17th piece

You must first place piece 17 in position 1 or 2

If piece 17 is in position 1, everything is fine, otherwise 1 scenario:

When The 17th piece is placed,
your topspin will look like this:



Case where piece 17 in position 2


Step 3

The 18th piece

You must first place piece 17 in position 1

If piece 18 is in position 2, everything is fine, otherwise there are two scenarios:

When the 18th piece is placed,
your topspin will look like this:



Case where piece 18 in position 3



Case where piece 18 in position 4

the piece is then in position 3, you must therefore carry out the algorithm opposite
Step 4

The 19th and 20th pieces

You must first place piece 17 in position 1

If piece 19 is in position 3, everything is fine, otherwise 1 scenario:

When the 19th and 20th pieces are placed,
your topspin will look like this:



Case where piece 19 in position 4



Your TopSpin is resolved.