Pike is a chess tactic that revolves around a strong piece and indirectly hits a weaker, undefended target behind it. They are in many ways the opposite of a pin and usually result in an immediate gain in material.
What is a spit in chess?
Sometimes referred to as the “reverse pin,” skewers are also about taking advantage of two enemy pieces that are lined up in an unfortunate manner. By attacking a valuable piece in front and forcing it to move away, you expose the less valuable piece behind that is ripe for capture.
There are two types of skewers: absolute skewers and relative skewers. Absolute skewers include the king, which is practically the most valuable piece in the entire game. You have no choice but to move out of the way when they’re under attack – that is, when your opponent checks you – and when they can’t dodge you have bigger problems than losing material because it means that it is checkmate and the game is already over.
Relative skewers involve two non-king pieces. Let’s look at this example below:
By attacking the queen and forcing her to get out of the way, she exposes the bishop on b7 to an attack. This gains material for White in the position. Of course, if the b7-bishop were protected, this tactic would not work at all: it is important that you can actually win the revealed piece with your clever move.
How to get out of skewers?
Usually, by the time the spit tactic is on the board, it’s too late, so prevention is the best approach. “LPDO” or “loose pieces fall off” as the Chess Council says: try to protect your pieces, preferably with pawns or other relatively cheap pieces, rather than relying on the queen or rooks on the front line.
You can also exit Pikes if you have an even greater threat at your disposal. Consider the previous example with the white queen moved to a3:
Here Bf3 would be a terrible mistake, because Black could play Qe1+ with checkmate next move. In this case, the skewer could simply be ignored. Even when there’s no mate to follow, stepping off the spit with check and forcing your opponent to respond to the move you make can often be enough to reduce the threat.
https://dotesports.com/chess/news/what-is-a-skewer-in-chess What is a spit in chess?