Explain why the stalemate developed on the western front

When the Schlieffen plan failed the German army ordered to begin to fall back. But after the German army has been chased by the allies they decided to start using defensive plans. The Germans stopped at the river and start making trenches to prevent the allies' progress towards the Germany. The Germans dug in using trenches to stop allies. Trenches have been a very powerful defensive structures and a direct attack would probably mean a …

…their mountings, carriages and supplies. In the end there were a lot more other ideas of how to defeat the trenches such as Underground war but in the end it all didn't work out the result was the formation of stalemate in which no one can make progress towards the other side. Another reason for why the stalemate was that all of the forces have equal numbers. They could get through all kinds of difficulties