Those who focus on heroism lose sight of the fact that the heroism of some is often a consequence of the stupidity of others. So in 1237, the Ryazan prince with his squad went into the open field to meet Batu, there, in fact, there was no battle, just the beating of the heroic Ryazan army. And the battle on Kalka, when almost the 90 thousandth Russian army met the 30 thousandth Tatar army, half of the Russian army was killed, and nothing good. So in the story with Dmitry Donskoy, a great role was played not by his personal heroism and not by the courage of the Russian army, but, first of all, by Dmitry's genius and strategic talent, who won the battle before it even began.
Strategic deception
Throughout history, any army, especially the defending one, has tried to rise in the heights. It is always more convenient to defend from a height, especially against cavalry troops. The prince was the first to enter the Kulikovo field, but did not occupy the height, he left it to Mamai. Mamai accepted this “sacrifice” and already then lost the battle. It is even strange that such an experienced commander did not think about why he was presented with the dominant height. Dmitry did this so that Mamai could watch and was sure that he could see. And he did not see the main things: the ravines in front of the Russian right flank, the ambush regiment sheltered by the forest, did not understand the asymmetry and weakness of the flanks of the Russian rati.

The effect of advanced shelf
For the first time in history before the head regiment, Dmitry Donskoy put forward an advanced regiment slightly ahead, a very dubious at first glance protection in 3-5 thousand people. What role should he perform? Was it worth it to attach to the head?
In order to understand this, you can refer to the circus number. Its essence is as follows: the hero knocks the stone with a hammer, it cracks or splits under the blow. Dale is put on the table of a man and covered with a thin stone slab, the same Hammer striker now beats the slab, it shatters into pieces, and the man rises from under it unscathed. At the moment of impact, the plate evenly distributes the impact force over its entire area. Instead of a powerful blow, only some uniform pressure is transmitted to a person.
We don’t know how Dmitriy thought of turning the Mongolian cavalry’s swift strike into the usual weakened pressure on the center of the Russian army, without violating its structure. But we have to admit, he applied this technique very skillfully.
Mamai - Dmitri's ally?
Mamai thought he saw everything from the hill. And he clearly saw that the weakest flank of the Russian army was the right one. He was not numerous and stretched for quite a long distance. In the center, on the contrary, there was the bulk of the Russian army: the forward, head and spare regiments.
The battle plan was born by itself: to break through the right flank and go to the rear of the main Russian forces, surround them, bring panic into the ranks and destroy. And Mamai originally sent his cavalry to the regiment of his right hand. And then he ran into the first “gift” that Dmitry had prepared for him. The positions of the Russian troops were two rows of ravines, which simply could not be seen from the hill. Moreover, even the horsemen themselves noticed the ravines, only standing in front of them closely.
Thousands of cavalry in a broad front at a decent speed flies into a ravine. Rear horsemen are pushing at the front, it is impossible to step aside - the offensive is going on a broad front. Already before the collision with the Russian Tatars suffer losses. Instead of a swift raid, cavalry is slowly moving up to ... the second row of ravines.
And this is a small victory. Horsemen first descend into a ravine, then slowly rise one by one from it and stumble upon a squad of princely squads, who calmly one by one, methodically beating up these emerging riders. Mamai's army suffers heavy losses, its best batyrs die, the tempo of attack is lost. After 1-2 hours of such beatings, Mamai takes the second point of Dmitry Donskoy’s plan to “get stuck” in a critical mass in the center of the Russian army.

Trick prince
After that, none of the historians really could not explain why the prince, before the battle, wore a simple chainmail war, and gave his cloak and banner to the boyar Mikhail Brenko. But this was one of the moments that later led to the first turning point in the course of the battle: the balancing of forces in the center and the loss of the offensive outburst here by the Tatars.
The prince knew the Horde army well, the methods of conducting the battle, and the generals of the enemy. He was confident that the tactical offensive impulse, each individual commander will be sent to him, the Russian commander, to his banner. That is exactly what happened, the Tatars, regardless of the losses, were hacked to the flag, and it was impossible to stop their outburst, the boyar was hacked up, and the banner was knocked down.
Historically, the loss of the commander and the flag, death or flight led to a psychological change, followed by the defeat of the army. It turned out differently; the Tatars turned out to be paralyzed. Thinking that they killed the commander, they published victorious shouts, many even chopped off, their pressure began to fade. But the Russians did not even think about stopping the battle, they knew that the Tatars were wrong!
Outfit troops
Let's return to the advanced regiment. He took upon himself the very first and most terrible blow of the Mongolian cavalry, but this did not mean that all his warriors were doomed to death. Foot soldiers can resist cavalry. For example, you can put a "wall" of copies. Several rows of warriors, armed with spears of different lengths (at the front they are shorter, at the back - longer) that end at the same distance in front of the line. In this case, the advancing cavalry encounters not one spear, which he can deflect with a shield or chop, but stumbles upon 3-4 and one of them can achieve his goal. The warriors' bodies were also well protected. The so-called “blue armor” of the squad from Veliky Ustyug was not inferior in its qualities to the armor of the Genoese knights who fought on the side of the Horde.
The prince himself during the battle was not even wounded, although he fought in the front ranks of the troops. And it's not just in the skill and power of Dmitry Donskoy. The enemy simply could not hit him when he took a sword or spear. His mail was forged from the best grades of metal. A plate of metal plates was worn over the chain mail, and a simple warrior was disguised over all this chain mail. He was hacked, stabbed, beaten, but no one was able to cut through all three layers of his armor.
But any blows are blows. The prince’s helmet was dented in several places; by the end of the battle, Dmitry was in a state of deep concussion, perhaps it was the cause of his early death at the age of 39. But at the same time not one Russian soldier did not see that the prince was bleeding, he did not give such a psychological loss to the Tatars.

Mamai gets trapped
The battle is already 4-5 hours. Mamai sees that there is a dead end in the center, a wall of the dead is formed between the living, a critical mass has worked, Mamai sees this from a hill and gives the order to transfer the blow to the left flank. And even in spite of the fatigue factor, the Tatars are already offensive for several hours, both people and horses are tired, their pressure is still strong. The numerical advantage affects, and the regiment of the left hand begins to retreat, bend under the onslaught of the Tatars, retreat to the oak grove. The numerical advantage on the side of the attackers, it seems to Mamai from the hill, he does not see the Ambush regiment beyond the oak grove.
But it is from the top that you can see how the Russian regiments are moving farther and farther back, how a gap appears, into which you can throw troops and go around the Russians to the left and strike them to the rear. And Mamai makes his last mistake. Directs to the breakthrough all the reserves at his disposal. The regiment of the left hand is rejected, the Tatars rush forward, accumulate and unfold to strike at the flank and rear of the central regiments, leaving the rear for the Ambush regiment open. The prince’s plan was completely successful; the Tatars turned back to the main strike force of the Russian troops. The strike of the fresh cavalry of the ambush regiment was fatal for the Tatars. Army Mamaia turns into uncontrollable flight.