Like the easiest to understand. For example, if you have an order for corn with two hands now, that is, you buy corn with two hands, and the market is in a downward trend. Your backhand operation means to level the two-handed corn list and then sell the two-handed corn list.
From the results, your position remains the same, but the position direction has changed from multiple orders to empty orders.
Futures is a two-way transaction. During the consolidation period, due to your own misjudgment, such as building more, but falling, you immediately close your position and then open a short position. This is called backhand.