One game of Spider solitaire followed from the deal to the finish, move by move, with the reason for each choice.
This is two-suit spider, spades and hearts, with 104 cards. Ten columns are dealt: six cards in each of the first four and five in the rest, with only the last card face up. The other fifty cards are the stock. The face-up cards here are 7♠, 8♥, K♠, 6♠, 8♠, 5♥, Q♥, 9♥, 7♥ and J♠.
Any card can go on a card one rank higher, whatever its suit. But only a run of one suit can be moved together, so the question for every move is not just whether it fits, but whether it is in suit.
7♠ from column 1 could go on 8♥ or on 8♠. It goes on 8♠, because a spade on a spade is a run that can move later. Column 1 turns over 6♥. Then 6♠ from column 4 joins it — column 5 now reads 8♠ 7♠ 6♠ — and column 4 turns over 10♠.
5♥ from column 6 goes on 6♥ in column 1 rather than on 6♠, for the same reason, and column 6 turns over 9♠, which goes straight onto 10♠. Column 6 then shows 3♥.
8♥ from column 2 goes on 9♥ in column 8, turning over 4♠, and 7♥ from column 9 follows it, turning over J♥. Column 8 is now 9♥ 8♥ 7♥, all hearts.
Now a harder choice: Q♥ from column 7 onto K♠ is off-suit. It turns over a card, and here that card is Q♠ — which would have fit on the king in suit. That is the price of an off-suit move. J♠ from column 10 goes on Q♠, turning over 10♥, and 10♥ goes on J♥ in column 9, turning over 2♠. Then 10♠ 9♠ from column 4 can move together onto J♠, because both are spades, and column 4 turns over 4♥.
4♠ from column 2 can only go on 5♥, which is off-suit, but it turns over a card, and early in the game turning cards matters more. Column 2 shows 3♠, which goes on 4♠ in suit, and then A♥. Column 1 now reads 6♥ 5♥ 4♠ 3♠. The two spades at the end can move together, but the whole run cannot, because it changes suit in the middle.
2♠ from column 10 goes on 3♠, turning over 5♠, and 5♠ goes on 6♠ in column 5, turning over K♥ — the last card in column 10. A king with nothing under it is a clean start for a new run.
With nothing useful left to do, you deal: one card from the stock lands face up on each of the ten columns. That is only allowed when no column is empty, which is why it pays to deal before you clear one rather than after. The stock holds five of these deals.
The new cards will cover some of your runs, and the work starts again: build in suit, turn over hidden cards, and use the off-suit moves only when they uncover something.
Much later, one column ends in a run of spades from the king all the way down to the two. The moment A♠ lands on it, the thirteen cards are complete and the site takes the run off the table.
Eight runs like that — four in spades and four in hearts — win the deal. The table counts them as you go.