There was a heavy rain in the valley above. Why didn't Zhuge Liang send troops to kill Sima Yi? Instead, he shouted that God would not help me.

The battle of Gu Fang was Zhuge Liang's best chance to catch Sima Yi, and it was also the last good encounter. Unfortunately, at the last minute, a heavy rain fell from the sky, dousing the fire and hope.

Some people say that Zhuge Liang can't have the final say? Aren't you very good at reading the weather forecast? Battle of Red Cliffs, you can borrow the east wind. Why not borrow it again this time to blow away the rainstorm?

In fact, this can't blame Zhuge Liang. Zhuge Liang watched the weather forecast the night before, and the satellite cloud picture clearly showed that it was sunny. The reason for the heavy rain has nothing to do with the weather forecast, but with the thermal convection.

As we know, Shanggu is similar to a gourd, with only one mouth, one exit and one entrance. The valley is narrow at the bottom, wide in the middle and narrow at the top. When the fire is raging at the bottom of the valley, hot air rises from the bottom and meets the cold air at the top of the valley, forming a small range of convective weather, and then it rains heavily, which is the same as the thermal convective weather in summer.

Although Zhuge Liang saw the weather forecast, he didn't understand physics or the principle of overheating convection. So when the rainstorm put out the fire and saved the life of Sima San and his son, Zhuge Liang vomited blood and sighed. Man proposes, God disposes, not strong! ? .

Then, the fire saved Sima Yi and his son. Why did Zhuge Liang make a hullabaloo about instead of sending troops to kill Sima Yi immediately?

First, there are soldiers outside Sima Yi. Sima yi just took a small group of people into the valley, and a large group of people stayed outside. In Romance of the Three Kingdoms, Sima Yi just rushed out and met Zhang Hu and Chen Le who came to meet him. At that time, Ma Dai's army was very small, only 500 people, and he dared not chase it.

Second, Zhuge Liang is careless. Zhuge Liang has always been cautious, but this time he was careless. He thought that Sima Yi had entered the valley above, and the fire would definitely burn him into a roast suckling pig. There is no need to send more troops, but people are not as good as heaven.

Third, Shanggu is not suitable for ambushing too many troops. At that time, Sima Yi curled up in Dazhai, became a little puss-head, unwilling to come out anyway, and wanted to fight with the Shu army. The Shu army came from afar, and the supply of food and grass was insufficient. Zhuge Liang adopted various strategies to lure the snake out of the hole.

To lure the snake out of the hole, we must be very careful not to let Sima Yi, an old fox, find any clues. Zhuge Liang sent two commanders, Wei Yan and Ma Dai, and gave them 500 men respectively. After two defeats, Sima Yi was led to Shanggu. If we had ambushed heavily and discovered the clues with Sima Yi's cunning, we wouldn't have been fooled.