Spiderette strategy
In brief
Reveal face-down cards as early as possible, build in the same suit whenever you can, keep an empty column as a working space and make every useful move before dealing. These are tips, not rules: the examples come from a real game in the app, replayed by a program.
Reveal face-down cards
At the start, 21 of the 28 cards are hidden, mainly in the columns on the right. Each card revealed opens up new moves: first look for moves that free a hidden card. In game SD1-S1-AAAAABD, the first move places the 6♠ from column 3 on the 7♠ in column 1: the card beneath turns face up, leaving only 20 hidden cards. By move 41, only 6 remain.
Build in the same suit
Placing a card on a card of another suit is allowed, but the resulting group can no longer move as a unit, and it will never be removed as it stands: a removed sequence must be all of one suit. With 2 and 4 suits, prefer a card of the same suit when you have a choice, and reserve mixed-suit moves for freeing a hidden card. The Examples page shows a blocked group of two suits.
Keep an empty column as a tool
An empty column accepts any card: it is the best place to set a card aside while you reveal another. But dealing requires a card in every column. In the same game, at move 17, column 2 becomes empty: dealing is then not allowed.
Stock: 17 cards, 3 deals remaining; no sequences removed. Column 1: 0 hidden cards, then 10 of spades, 9 of spades, 8 of spades, 7 of spades, 6 of spades, 5 of spades, 4 of spades, 3 of spades, 2 of spades, ace of spades; column 2: empty; column 3: 1 hidden cards, then 7 of spades, ace of spades; column 4: 1 hidden cards, then 10 of spades, 9 of spades; column 5: 3 hidden cards, then 7 of spades, 6 of spades, 5 of spades; column 6: 3 hidden cards, then king of spades, queen of spades, jack of spades, 10 of spades, 9 of spades; column 7: 4 hidden cards, then queen of spades.
Move 18 places the A♠ from column 3 there, and move 19 deals. Before filling an empty column so you can deal, make the most of it: this is the time to make every move that requires a free space.
Prepare for each deal
Dealing places a card on each column and covers the sequences in progress. Before tapping the stock, make every useful move, especially those that reveal a card or arrange a group in the same suit. There are only 4 deals, and the last places only 3 cards, on columns 1 to 3: in game SD1-S1-AAAAABD, this is move 32.
Think about complete runs
A complete sequence from king to ace is removed automatically and earns 100 points. In game SD1-S1-AAAAABD, the first sequence is removed at move 41, in column 7: the score goes from 460 to 559 (−1 for the move, +100 for the sequence). A column cleared by removing a sequence becomes an empty column again, ready to use.