Divination is a form of communication. It is communication between Man and Heaven. Through communication, human beings get guidance from above. Therefore, in the old days, divination is a means to get guidance about the fortune, misfortune, success and failure of human endeavours. In Chinese it is known as Ji, Xiong, Cheng, Bai 吉凶成敗.
Divination is not to be used lightly. For example, when the emperor asked his imperial diviners about which horse entered the water first, it was, in a way, an abuse of divination. The diviners could not tell the emperor they could not use divination in such meaningless events. They had to give him an answer but they also knew that they had only 50% chance to be correct because Heavenly would simply not give them guidance.
When Lu State was about to attack Yue State, it involved many lives and the glory or humiliation of a country. It was something that needed guidance. What the diviner Zi Gong wanted to know was the Ji/Xiong and Cheng/Bai of the military action. He did not need to ask whether Lu would win the war and within how many months. He did not even need to ask a question. All he needed was to pass his message to Heaven that he was concerned about the Ji/Xiong and Cheng/Bai of the war.
Although there was a popular guessing game known as She Fu 射覆 played in the old days, it should also be considered an abuse of divination. It is just to satisfy the curiosity of people. If is is used with the purpose of practicing and acquiring technique of divination, it is ok but the accuracy is doubtful.
Today, it is not uncommon to use divination to test the stock market. Let us say, you have studied the market and then decide to invest in a certain stock. Well, you want to have guidance from Heaven whether it will be a profitable investment. Then your divination is simply the Ji/Xiong and Cheng/Bai of your investment in that particular stock. You will use your mind to send this message to Heaven to get an answer. No particular way to ask the question is needed and no time frame needs to be set. The divination should display a picture before you to help you decide whether or not you should go ahead. It may also tell you whether or not there will be quick profit and what to expect. The time frame is taken care of automatically.
Of course, if you have no plans to invest in the stock market but you want to know how the market will behave in the coming year, you can also use divination. As long as you pass your message accurately from your mind to Heaven, you will get the answer. The divination will tell you about the Ji/Xiong and Cheng/Bai if you invest in the market.
What about games like horse racing or other sports? I will talk about this later.