  I discuss the practical convergence of the SU(2) ChPT series in the meson
sector, based on 2+1 flavor lattice data by the Wuppertal-Budapest and
Budapest-Marseille-Wuppertal collaborations. These studies employ staggered and
clover-improved Wilson fermions, respectively. In both cases large box volumes
and several lattice spacings are used, and the pion masses reach down to the
physical mass point. We conclude that LO and NLO low-energy constants can be
determined with controlled systematics, if there is sufficient data between the
physical mass point and about 350 MeV pion mass. Exploratory LO+NLO+NNLO fits
with a wider range reveal some distress of the chiral series near M_\pi ~ 400
MeV and suggest a complete breakdown beyond M_\pi ~ 500 MeV.
