Every chance on this site comes out of four steps. Here is what the game does on each cast, and the three numbers TTR has never published.

1. Roll the catch type

Every cast lands a fish, a jellybean jar or a boot.

• 93% a fish
• 1% a jellybean jar
• 6% a boot

2. Roll a rarity

A fish catch rolls a rarity from 1 to 10, favouring lower numbers. Better rods shift the roll towards rarer fish.

3. Pick from the pond

The game picks from that pond’s entries at the rolled rarity. Repeated entries increase a species’ chance. If the rarity has no entries, it tries the next rarity down until it finds some.

4. Check the weight

A catch above your rod’s weight limit breaks the line. Compare rod limits and costs.

Three numbers TTR has never published

The four steps above are documented. Three of the values feeding them are not, so this site picks one and says which:

• Street ponds. Street ponds here offer their neighborhood’s fish as well as their own. TTR has never documented the rule; other guides read it the other way.
• Rarity curve. Update v3.7.0 made rare fish easier to catch without publishing the new curve, so these pages keep the curve measured before it.
• Pond boosts. A boosted species counts double here. The update announced the boosts without giving the multiplier.

Percentages and averages are for planning a session. A single fish can arrive on your first cast or your hundredth.

Source: TTR’s Fish Migration Update (v3.7.0).