The correct answer to this open question is the following.
Experts and historians agree on the fact that Germany and its allies (the Austria-Hungary Empire and the Ottoman Empire) had their chances to win World War I, but never was on the brink of winning it.
Germany had a powerful army and good strategists in the ranks of military officials. Furthermore, the addition of the Ottomans army and experience and the Austria-Hungary troops created some kind of a monster.
It was never easy for the allies to stop and contain Germany's advances until the war had a stalemate on the Western front.
Did really Germany was close to winning the war? Well, let's have in mind the following moments during World War I.
German troops were very close to enter and capture Paris in 1914. German troops defeated Romania, defeated Serbia, and forced Russia to leave the war. During the Western Front stalemate, Germany had its chances...until the United States entered the war.
So it got ugly, ugly to the degree that the US Army had to enter teh way to closely incline the balance in favor of the allied forces.