  We match the results for the subthreshold parameters of pion-nucleon
scattering obtained from a solution of Roy-Steiner equations to chiral
perturbation theory up to next-to-next-to-next-to-leading order, to extract the
pertinent low-energy constants including a comprehensive analysis of systematic
uncertainties and correlations. We study the convergence of the chiral series
by investigating the chiral expansion of threshold parameters up to the same
order and discuss the role of the \Delta(1232) resonance in this context.
Results for the low-energy constants are also presented in the counting scheme
usually applied in chiral nuclear effective field theory, where they serve as
crucial input to determine the long-range part of the nucleon-nucleon potential
as well as three-nucleon forces.
