Could someone explain the difference between a FL and a Dr. B please?

I have seen bits with a large flat center, a small bean, a small round ball, a really fat bean, some have a noticiable curve to the canons, some have a slight curve.

 I just saw a bit, it was a three piece, there was a slot on the cheekpiece for a chin strap??  Since when do snaffles require chin straps?

Help please.

The difference between the french link and the Dr. Bristol is that in the French link, the middle link lays flat, while in the Dr. Bristol it's at an angle to the rest of the bit.  The size and shape of the middle piece seems to be interchangable, I've seen both bits with different shapes and sized center pieces.

 I have a french link, full cheek snaffle for Annapolis and it has keepers, but I've never seen one with slots or a chin strap either.

 Yup, the Dr Bristol has the middle piece at an angle so the edge cuts against the tongue stronger than the French link.

As the others have said - the Dr B is a VERY harsh bit and is illegal in dressage competition.  The French link has a flat middle piece that sits flat on the tongue, the other bits with the 'nut' centre piece are your KK training bits, these bits are good for horses with a high pallett but a lot of horses dont like them as they can hit the roof of the mouth causing discomfort, I have found them to be used on the basis that "....everyone else is using them" as in a fad, beleiving that it will make the horse perform better, win more comps etc etc.

The bits you refer to with the slot are not for chin straps but for lowering the point where the rein goes, like a gag, I think you will find these are probably myler bits, only the myler snaffle is legal in dressage and ONLY when the rein is attached in the usual manner, again these bits were originally designed for western horses but have been used as a 'cure-all' on english (dressage) horses, some horses love them others hate them.  For me its a case of trial and error where bits are concerned, you need to try try try bits until you find the one that YOUR horse likes and works in the best.

It seems then one of the most important things is too see how the bit fits in my own horses mouth.

Currently I do use one of the kk which I thought was a French Link.  It has a fairly small bean.

I was also under the impression it was considered a mild bit, I believe I have educated hands and wanted something gentle to start my mare in.

On the subject of bit fit how much past the lips should the bit extend?

 thank you again for replys