The use of spacers can be a controversial issue. Some argue that spacing makes a break easier and is, therefore, a form of cheating. I do not consider the use of spacers to be a form of cheating. Granted, spacers do make certain kinds of breaks easier, but can actually make others more difficult. Spaced breaks present a different test of your skills than breaking solid targets and should be evaluated accordingly.
The use of spacers is much safer for your hand than breaking solid stacks. As long as you can break one board or block, there is little chance that you will seriously injure your hand. It is much more injurious to strike a solid stack of blocks and not break it, than it is to partially break a spaced stack. This is because the motion of your hand is not stopped so abruptly.
Without spacers, your hand is racing at full speed and hits the solid target like a car crashing into a wall. It goes from full acceleration to 0 mph instantly, resulting in a crushing force against your hand.
With spacers, each successive block slows your hand incrementally, until it is no longer fast enough to continue through. Once you have the ability to break a few blocks, you can test your limit with minimal risk of injury.
This affords you the opportunity to apply full striking force against a forgiving target. Spaced breaks do not require as much conditioning as solid breaking. For this reason, it is a very popular practice among individuals of unusual strength and weight, but, perhaps, less actual hand conditioning.
Spacers also measure the ‘follow-through’ or penetrating force of a strike. Obviously, breaking ten spaced boards or blocks is not the same as breaking them without spacers. Still, certain techniques, such as iron palm slapping, are more effective against solid objects than spaced ones. Whereas a hammer fist breaks the first block and continues on to the next, an iron palm slap generates a characteristically ‘shorter’ force with reduced driving power.
Some people are under the impression that, when using spacers, you need only break the top block and then that block will break the next and so on. This is technically true in that each block contacts the next to break it, but they will not go anywhere without a sustained driving force behind it. Blocks will truly break themselves only when the material becomes heavy enough for gravity to automatically continue breaking each successive layer.
Even with long scalloped blocks (the weakest and heaviest of the standard concrete blocks), I have broken up to nine in a spaced stack, only to be stopped on the tenth block. At twenty pounds a piece, even the combined weight of all nine blocks dropping was not sufficient to break the tenth block. Using spacers is not like setting up a row of dominos.
Gravity will take over in instances such as breaking huge, long blocks of ice with giant spacers. Generally, the larger the spacer, the easier the break. This holds true until the spacers are so large, and the stack so tall, that your power is diffused by the increased depth. Either way, if you are using over sized spacers, it is plain for everyone to see, so it does not constitute fraud.