It seems like every year by the time the NFL Draft rolls around, the Bengals seem to have holes at one or more positions which almost force them to take a player at that position.
In the past several drafts the Bengals entered it with needs at these positions:
2011: WR- Took A.J. Green #4 overall.
2010: TE- Took Jermaine Gresham#21 overall
2009: OT- Took Andre Smith #6 overall
2008: LB- Took Keith Rivers #9 overall
2007: CB- Took Leon Hall #18 overall