Looking to start a discussion, or maybe just get some tips from the experienced guys. Let's say I want to take a directional view on the back half of the curve. I am pretty sure that I can just buy the UB/ZB spread in a 1:1 ratio and that will give me a bullish exposure. This would also work with UB/TN or even UB/ZN. My question is basically, what other spreads would be similar in nature. If I buy enough ZB and sell a little UB, AFAIK that would also work to accomplish this. So this is basically my question. What other kinds of spreads can you use to express a directional view on the back half of the curve? Or even, should I be using the exchange supported ICS spreads for this? Something like buying ZB/TN or ZB/ZN in a heavy front ratio would also do the same? Does NOB and BOB with the above ratios work for this, or would this be more of a curve play instead? How deep does this rabbit hole go? Recommend a book or something? Thanks.