Let N be the set of natural numbers, N0=N∪{0}, and let R be the set of real numbers, identified with the Euclidean space R1. Fix a real number μ>0 and a natural number m≥1, and let pμ be the Poisson probability mass function of Move Score and Move Information of the Poisson Probability Mass Function, pμ(k)=exp(−μ)μk/k! for k∈N0 and pμ(x)=0 for x∈R∖N0, a discrete probability mass function on R with support N0 by claim 1 there; here k! is the factorial with 0!=1, exp the exponential function, and x0=1. Sums over subsets of N0 of nonnegative functions are those of Sum of a Nonnegative Function over an Arbitrary Set, and finite products over an empty index range are 1. For natural numbers 0≤i≤m write (im)=m!/(i!(m−i)!).
Define the removal ratio ϱ=ϱμm:N0→[0,∞) by ϱ(k)=pμ(k−m)/pμ(k), so that
ϱ(k)=i=1∏mμk−m+i=(k−m)!μmk!(k≥m),ϱ(k)=0(k<m).
Consider the single move a=(a1) with a1=m and a single weight w=(w1), w1∈R, in the sense of Move Score of a Discrete Probability Mass Function.
1. (Move score) The move score of pμ for a and w is ρpμ,a,w(k)=w1(1−ϱ(k)) (k∈N0), and k+a1∈N0 for every k∈N0.
2. (Mean) ∑k∈N0pμ(k)ϱ(k)=1.
3. (Exact second moment and move information)
k∈N0∑pμ(k)ϱ(k)2=i=0∑m(im)2i!μ−i,
and consequently the move information of pμ for a and w is
J(pμ;a,w)=w12i=1∑m(im)2i!μ−i,withμm2≤w12J(pμ;a,w)≤μm2+2μ2m4exp(μm2)
when w1=0 (for w1=0 the move information is 0).
4. (Pointwise bounds) For every k∈N0, ϱ(k)≤(k/μ)m. If x≥0 is real with m(x+m)≤μ, then every k∈N0 with k≥μ−x satisfies
ϱ(k)≥1−μm(x+m).