Why do you get TDC twice when turning the crankshaft?

You achieve Top Dead Center (TDC) twice in a crankshaft rotation because the engine's four-stroke cycle consists of two complete revolutions for each power cycle. During the first revolution, TDC occurs once at the end of the compression stroke and again at the end of the exhaust stroke. The first TDC corresponds to the compression of the air-fuel mixture, while the second TDC aligns with the exhaust phase, indicating that the cycle is ready to begin anew. Thus, every full crankshaft rotation results in two TDC positions, one for each cylinder cycle.