Plot-holes are a given in every type of storytelling - writers aren't perfect, they can overlook details. In the case of comic books though, they are far more prevalent, with the collaborative nature of the medium, decades-long convoluted histories of characters, and numerous books releasing concurrently making it a nightmare to keep the continuity consistent.
Batman suffers from these problems. He's been around for over eighty years, and usually has at least three books in which he is a leading character releasing every month - and that doesn't even include the books focused on the many members of the bat-family, Justice League, or his elseworlds titles. Add in the seemingly never-ending series of reboots that DC love doing and then one can begin to fully comprehend the mess of continuity that the Caped Crusader is at the centre of.
At this point, most simply accept that there will be inconsistencies among the Dark Knight's various tales and just enjoy good stories when they happen. Well, good for them, but today we're going to delve into some of the Batman's holes (of the plot variety, obviously).
10. The Number Of Batmen Referred To By Future Batman - DC One Million #3
DC One Million is a book written by Grant Morrison that takes a look at the Justice League of America of the 853rd century. In it, the Batman of the future refers to Two-Face-Two, a version of Two Face that appears in the Batman-666 future (the one that sees Damian Wayne become Batman because he sold his soul to the devil).
That's all fine, but when the 853rd century refers to Batman-666, he states that Damian is the second Batman. Which is wrong because Damian was the third Batman, after Bruce and Dick.
To be fair to Morrison, he did write DC One Million a whole twelve years prior to when he wrote the story that introduced Batman-666, so perhaps this plot-hole is one more deserving of praise than criticism, because that shows a heckuva vision.