Being in west Arkansas, the closest casinos we have are eastern Oklahoma Indian casinos, which are known for the Class II bingo slot machines. My favorites are the Lucky Ducky, Crazy Bill's and the other 3 reel slots with the red spin features.
I've been playing these pretty heavily since early summer, and I think I've finally got them figured out. To be honest, it does take a little of the fun away knowing how the bingo numbers and patterns work, and once you learn a certain game's patterns and payouts, you often have a good idea what's gonna come up when the machine red spins. I still get pleasantly surprised, but it doesn't happen often anymore. Here's what I've learned so far...
You can watch the screen before playing; it will cycle through all the winning bingo patterns and what they pay on each bet. I've seen people under the assumption that they have to 'wait' or 'pick' a pattern to go for lol. They don't realize it's just 'advertising' so to speak.
Red spins occur when you have more than one winning bingo pattern on your card. The spins are awarded from lowest to highest. For example, if you get a red spin after getting mixed bars, the red spin will be something equal to or greater than the mixed bar payout. If you get more than 2 winning patterns, it will continue to red spin until all patterns/payouts have been awarded. I once seen a machine go red on mixed bars, then the machine proceeded to red spin AT LEAST 7 times after, with the last spin being triple bar, duck, duck on a quarter machine for over 400. My personal record so far is 5 red spins on Lucky Duck for over 900 on a dollar slot.
You get a new randomly generated bingo card every time you hit the spin button. Right below where your card is displayed, you can see all the bingo numbers that have been called so far. You'll see a set of gold/orange numbers, then you;ll see a set of white numbers that are 'called' by the machine every second or so. Here's the catch...you only get a payout for a bingo pattern if that pattern is made up of the gold/orange numbers. The white numbers being called out will be marked on your card, but you can't win anything off them. As more white numbers are called, the more impressive your bingo cards look as you hit the spin button, but still, you only get credit for patterns made up of gold numbers. Think of the white numbers as a countdown to the next bingo game; once all the bingo numbers have been called, a new game is started and the gold/orange numbers are changed. When a new game is started, 38 numbers are randomly generated to be gold 'winning' numbers and then the server begins calling out the rest of the numbers in white until they have all been called again.
Different casinos have different winning patterns; at one casino here, a triple bars payout on Lucky Ducky is getting a peace sign on the bingo card, whereas at another casino the same payout is achieved by getting an 'L' pattern. Again, the numbers making up these patterns have to be in the gold/orange section. You can also get what I call a 'double trigger' on the same pattern. My local Lucky Ducky machines have an 'anchor' pattern that gives you 2 double bars and a duck for 120 credits max bet. However, if all the gold numbers that make up that pattern are also in the FIRST 27 gold numbers listed, it will turn red and hit the anchor pattern again, but this time you will get the scattered 3 ducks for an additional 480 credits. There are 3 patterns that I know of that hit this way: champagne glass, anchor, and quotation mark I believe. These are also the highest hits you can get without hitting the jackpot, hence the reason they're so hard to hit.
There are some anomalities I haven't been able to understand yet though. For example, the 'cross corner' bingo pattern on Lucky Ducky is a small cross in the center of the card plus all four corner spaces. Normally, you will get credit for just the small cross first, then get a red spin that hits the cross corner pattern, which is displayed on the reels as two mixed bars and a duck. However, sometimes I've hit this without a red spin; I'm puzzled over why it doesn't always red spin when you clearly have 2 winning patterns in one. I've also hit some really big hits that just roll down without red spinning at all; most big hits are complicated patterns that also contain other smaller winning patterns within them.
I think I'm starting to ramble lol...but I hope that this may help anyone who plays these games and maybe has a hard time understanding when and where the red spins come from. Yes, once you learn all the patterns, it does take some of the thrill of a red spin away...unless you have a pretty full card and it red spins; so many bingo combinations are possible at that point and it happens so fast and you don't have time to see which numbers on your card are in the gold or white category. I wish there was an option to hide the bingo card from view; that would really make it exciting.