Doing pizzicatos is one thing, but the transition between arco and pizzicato (in either direction), especially when it has to be done quickly, can be quite problematic.
Most of the difficult (fast) changes between arco and pizzicato that we will come across will be in the orchestral repertoire – especially in operas. These situations can fortunately be resolved very easily by simply organising a “divisi” in which one side of the section plays the pizz and the other plays the arco. In other words, one side of the section plays the “old” movement all the way to the end (whether it be pizz or arco) but misses out on the start of the new movement, while the other side does the exact opposite (starting the new movement at the correct moment but missing out on the end of the old movement). That way all the notes – both arco and pizz – are sounded without anyone having to do any circus tricks. On paper it sounds perhaps complex, but in reality it couldn’t be more simple. Unfortunately this level of initiative is rarely to be found in orchestras where a military ethic of “following instructions to the absolute letter no matter what the difficulty” tends to prevail.
If you are the only cellist playing your line then it is not possible to make use of this type of intelligent cooperation to eliminate the problem. Now we actually have to solve the problem with our own physical dexterity (and a little bit of thinking as well). So, how can we do this?
To begin with, we can organise our bowings in such a way that an up-bow (rather than a down-bow) comes before the pizz. This favours the transition from arco to pizz because an up-bow will always tend to bring our right hand towards the strings (which is where it needs to be in order to do a pizzicato).