SALVO Strategy: Placement, Salvos and Specials

1. Aim by probability, and spread each salvo. Fire where the ships still afloat could lie in the most ways: 74.8% of games won against SALVO's computer.
2. Fire around every hit. Random fire took 19.3 rounds on average to sink a fleet; following up hits cut that to 13.8 and lifted wins against the computer from 0.2% to 48.8%.
3. Spread your fleet out. No ship touching another, even at a corner: 62.2% won against the computer, 48.6% with the shuffle.
4. Never cluster. When every ship touched another, wins fell to 30.6% against the computer and 13.4% against a probability aimer.
5. Use your specials. The computer won 57.1% of games against an identical computer that never used them.
6. Facing a probability aimer, use the edges. 53.0% won, against 24.7% with the shuffle.

Computer captains played SALVO with the game's own rules code, the code the game server enforces: both salvos land together, one shot per ship afloat, loot in every ocean, a special for every ship. Each captain knows only what you would: where it fired, which shots hit, which ships sank and where. The runs are seeded and repeatable.

In all: 166,000 whole games, 64,000 aiming runs (full salvos at a fleet that never fires back), and 200,000 fleets dealt by SALVO's shuffle for the heat map. The limits:

• These are computer captains, not people. Real rivals adapt; the numbers show what a habit is worth against a consistent one.
• Unless a test says otherwise, every captain played its specials like SALVO's computer: a dive once its submarine is hit, the heavy shell and depth charges next to a hit. Nobody used recon or sonar, and nobody here uses radar contacts.
• Every captain fired a full salvo every round.
• Each matchup ran 5,000 to 20,000 games, so a gap of a point or two can be chance.

Put several shots of your next salvo around every hit. A hit doesn't say which ship it struck, and your shots land together, so cover the four squares next to it at once: one holds more of the ship. The rest keep hunting.

Then read the line. Below, the misses beside E5 show its ship runs down column E. Still afloat after two hits, it isn't the Destroyer, so E7 is part of it.

When a ship sinks, SALVO shows all of it. A hit outside it belongs to another ship: keep firing around that one.

SALVO's computer won 57.1% of 20,000 games against an identical computer that never used its specials, with only the dive, heavy shell and depth charges in play. Specials cost shots from your salvo and sink with their ship: use each one while you can. The SALVO rules detail how each works.

Heavy shell and depth charges on a wounded ship

Once you know which way a wounded ship lies, aim the heavy shell two squares past your last hit: the plus covers the next three squares of the line. Depth charges, a row of three, suit a ship lying across.

The submarine dive

A dive costs one shot and, for one round, lets every shot but depth charges pass over your submarine. Dive the round after it is hit, as the computer does; a shot that passes over still gives it away. When yours passes over theirs, fire there again: it can dive only once.

Every ship you lose takes a shot off every later salvo, so the side that loses ships first falls further behind. In computer-against-computer games, the winner had a median of 2 of its 5 ships left.

• Sink, don't just wound. A ship with four hits still adds its shot and keeps its special.
• Every ship is one shot. Two hits on the Destroyer cut your rival's salvo as much as five on the Carrier.
• Aim every shot. Shots not aimed when the 25 seconds run out are lost.

Your misses find loot in your rival's open water: 3 supply crates (+1 shot next salvo), 2 mines (−1, never below one) and 2 radar buoys. A buoy reveals one unhit ship square, a contact: fire at it next salvo, then around it. The simulated captains ignored contacts, an edge these numbers leave out.

SALVO's computer plays hunt and target the same way every game. It fires at random until it hits, then at the four squares around each hit on a ship it hasn't sunk. It brings its heavy shell and depth charges down on a ship it has wounded, dives its submarine once the submarine is hit, and never uses recon or sonar. What that means:

• It hunts at random, so the edges don't hide you (50.4%); spreading out does (62.2%).
• It fires around every hit, not along the line, so ships beside a wounded one get hit too.
• Copying its aim wins about half the time (48.8%); a checkerboard (56.9%) or probability aiming beats it.