The November 3, 2010 update of Pocket Frogs adds a frog racing mini-game. Here is how it works.
Find the best racing frogs by level. Once you choose a level, you'll see a list of best frogs by sum of stamina + speed, followed by best frogs by speed, and best frogs by stamina for that level.
Only a tame frog can be entered into a race. The frog must be fully grown.
Whenever a frog jumps in the race, it spends some of its happiness. A frog's happiness level affects how often it jumps. A 100% happy frog will jump frequently, but a frog that isn't very happy will not jump very often at all. Therefore, to have the best chance of winning, you should maximize your frog's happiness before taking it to the races. So, take the frog out to the pond to eat some flies, or just feed it some growth potions to maximize its happiness.
The cost of entering a frog depends on its rarity. Here is the cost for the different rarity levels:
Your frog will compete against four frogs of the same rarity level. You can't control your frog during the race so once you start the race, just watch while your frog hops to the finish line. As mentioned above, your frog will spend some happiness each time it jumps. Its speed and stamina affect its performance in the race.
If you get first place, you can choose to either take a prize of coins, or to have one of the competing frogs mailed to you. There are often glass frogs or chroma frogs in the races, so this is a great way to get those rare types of frogs! If you win 2nd or 3rd place, you will win some coins. If you get 4th or 5th place, you don't get a prize.
As mentioned above, a happy frog will jump more often than an unhappy frog. Also, whenever the frog jumps, it needs to spend some of its happiness. The amount of happiness that it needs to spend is based on the frog's stamina. A frog with higher stamina does not spend as much happiness per jump as a frog with lower stamina. If the frog happens to eat a fly during the race, its happiness will increase a little bit.
Speed affects far a frog goes with each jump.
Stamina affects how quickly or slowly the frog's happiness reduces with each jump.
Speed and stamina go along with a frog's body color, pattern color, and pattern type. This means that if you have several frogs of the same breed (i.e. they all have the same colors and pattern), they will all have the same speed and stamina values as each other.
This means that getting the best racing frogs depends on finding the frog breed in each rarity level that has the highest speed and stamina. Check my list of the best racing frogs.
To make the most money from the races, always maximize your frog's happiness for the best chance of winning, and use a frog with good speed and stamina. Ideally, use a frog whose speed and stamina are the best that can be found in frogs of that level. If you get first place, you might want to choose a frog that is worth the most coins. Or, you might want to choose the frog that has the best racing stats. Check the frog catalog on this site, or the list of frogs by max value to see if I have the prices for the four frogs that you can choose from. Or, look at the best racing frogs page if you want to pick the frog that has the highest racing stats.