How the Dreaded Checkmate Happens
"Checkmate!" That's the last word players want to hear from their opponents. A checkmate can happen anytime—even just after 4 initial moves in the game. The term means the king piece checked is dead meat and the game is over. There are several things that must happen before a checkmate in chess is certain.
First, the king or any ally piece cannot capture the enemy piece that is making the ultimate check. If an enemy bishop or queen is making the checkmate, we have to find an ally piece able to capture the checking piece. Hence, it is a good thing to always surround our king with major or minor pieces for this purpose, or at least have them readily accessible any time. Pieces defending the king should also have back-ups. Checking enemy pieces are likely to have back-up assassins to consummate the assault. We must be ready for this, too.
Second, the king shouldn't be able to escape to a safe square when the checkmate is made. All squares to which the checked king can transfer to should either be controlled by the enemy or occupied by ally or enemy pieces. Thus, it is a good measure to always see to it that the king has safe squares or spaces to move into any time. When we see that our king has lesser freedom of movement we should send in reinforcements to protect it—for capturing or blocking.
Blocking is an excellent remedy for a checkmate in chess. Capturing the checking enemy piece or making the king escape to another square sometimes becomes less possible. But blocking the check with an ally piece can most times break the momentum of an assault and frustrate an impending checkmate. If we can manage to put the blocking piece right beside our king facing the attacker, the better we can ward off the attack.
If an enemy queen perpetrates the checkmate it would be best to block with an ally queen right next to the king. This enables us to counter check the enemy queen at once—assuming the opponent has not contrived a plan B of attack. If the enemy has devised a multi-point checkmate, we're doomed. Hence, we should also be armed with multi-point defense or escape systems.
A checkmate in chess has to pass the 3-pronged test of consummation: it should be capture-free, escape-free, and block-free. If these 3 are satisfied then the checked king is indeed dethroned.