Reachmahjong.com

Keeps the 7 pair as a possibility as well as well as toitoi, and allows you to open your hand and incorporate one or two of the bonus tiles into your hand.

then later

Might as well split these. One of the 2-pin is out. When developing chii toitsu, I tend to look for already discarded tiles and proceed to follow up. Once the 3-pin is discarded. The 2-pin may not be so useful either. Another thing to note, a 1-pin is in the discards as well.

Due to the Ton ankou, it is best to keep an option and not be locked for chii toitsu, just yet.The 4455 sou pattern may bring rise to iipeikou (or the "ryanmen" pattern of 34455 or 44556). Acquiring at least one of the dora would be nice here. In addition, no need to break up a 667 man pattern just yet. It'd be best to keep that handy for now.

I agree with Kyuu, except I'd discard the first.

It's splitting hairs, but my rational is this: I've already decided to discard them both, and the has already been discarded and went thru, so it is relatively safer than is the fresh .

It's my preference to shed the more dangerous tile earlier in the hand on the theory that, if claimed early it is more likely to be just for a set, and the longer the hand progresses and develops, the more likely that, if claimed, it could be for ron.

West is open and capable of going for a quick win. Toitoi might take too long. We are 3 tiles away and could also go for a quick win. By my count we need 3 from 14 or 15 (depending on whether dots or ch match comes first) unexposed tiles to get riichi, tsumo, EW, possible doras 3s 5s 5c, on 30. To do this discard 6c and go for chi's in sticks x2 and dots or characters depending on what comes first. This hand also has the advantage of going open if, for example, 3s is discarded by W.
Discarding characters looks to be a little safer than others based on early discard pattern.