# What are the drawbacks of an automatic card shuffler?

I've seen people specifically mention they use automatic shufflers with easily replaceable cards, but what about if it matters if the cards get damaged?

What are the drawbacks to using automatic shufflers? Does machine shuffling cause any more damage than would occur through a normal riffle shuffle? I've also seen some mention that automatic shufflers don't truly randomize the deck. Is this true?

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One drawback of auto-sufflers is that you don't get a truely random distribution. I don't remember the exact math, but if you cut a deck perfectly even and do a perfect 1-1 riffle shuffle, after so many iterations you end up back where you started. – DForck42 Oct 28 '11 at 14:35
@DForck42 Mechanical shufflers are designed to randomize the deck using different shuffle sequences — not just repeating a perfect riffle X times. For example, this shuffler has two settings, fully random setting is 1 riffle, 1 strip, 2 riffles, 1 strip and 4 more riffles. – ghoppe Oct 28 '11 at 15:42
@DForck42 If you can do 8 perfect shuffles you can restore a deck to it's original state youtube.com/watch?v=7lNk7bfkFq8 – AlexC Oct 28 '11 at 15:58
possible duplicate of Card shuffler for many sizes – Dave DuPlantis Oct 29 '11 at 2:36
– Dave DuPlantis Oct 29 '11 at 2:37

Mechanical shufflers come in several types. The simplest are the hand cranked gravity fed multi-wheel versions... and are the only ones I've much experience with, having owned two. (Both inherited.)

These particular ones both use a wheel to throw cards into the central bay from two elevated bays.

• some cards end up face up - I've averaged 1 face-up per 3 shuffles or so.
• cards can get scratched on the metal surfaces
• can't handle anything that's not "standard height" - it'll do bridge and poker decks of the 3.5" tall variety, but it won't do larger cards, as they get stuck, nor smaller, as they don't stack up in the center bay.
• crunches over-thick cards badly. In other words, 110# cardstock won't work well, as home cutting results in being too thick to work.
• Kem and other solid plastic cards don't grip right - increased flipping, and more manual downpressure required
• older machines' rubber wheels lose tackiness, and don't drag cards as effectively
• not quiet.

All the automated ones I've seen have the same issues plus

• not stopping if a jam occurs
• needing a source of electricity
• being even noisier.

I've not used it enough to determine edge wear effects, but Kem used to note that shuffling machines voided their warrantees.

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