  We study a new class of NP search problems, those which can be proved total
using standard combinatorial reasoning based on approximate counting. Our model
for this kind of reasoning is the bounded arithmetic theory $\mathrm{APC}_2$ of
[Je\v{r}\'abek 2009]. In particular, the Ramsey and weak pigeonhole search
problems lie in the new class. We give a purely computational characterization
of this class and show that, relative to an oracle, it does not contain the
problem CPLS, a strengthening of PLS.
  As CPLS is provably total in the theory $T^2_2$, this shows that
$\mathrm{APC}_2$ does not prove every $\forall \Sigma^b_1$ sentence which is
provable in bounded arithmetic. This answers the question posed in [Buss,
Ko{\l}odziejczyk, Thapen 2014] and represents some progress in the programme of
separating the levels of the bounded arithmetic hierarchy by low-complexity
sentences.
  Our main technical tool is an extension of the "fixing lemma" from [Pudl\'ak,
Thapen 2017], a form of switching lemma, which we use to show that a random
partial oracle from a certain distribution will, with high probability,
determine an entire computation of a $\textrm{P}^{\textrm{NP}}$ oracle machine.
The introduction to the paper is intended to make the statements and context of
the results accessible to someone unfamiliar with NP search problems or with
bounded arithmetic.
