curry.rb

module ExponentialBackoffStrategyModule
  module_function def call(exponent, value)
    value ** exponent
  end
end

class ExponentialBackoffStrategyClass
  def initialize(exponent)
    @exponent = exponent
  end

  def call(value)
    value ** @exponent
  end
end

curried   = ExponentialBackoffStrategyModule.method(:call).curry.(4)
partialed = ->(x) { ExponentialBackoffStrategyModule.call(4, x) }
lambdad   = ->(x) { x ** 4 }
klassed   = ExponentialBackoffStrategyClass.new(4)

require 'fruity'

compare do
  curry   { curried.call(10) }
  klass   { klassed.call(10) }
  partial { partialed.call(10) }
  λ       { lambdad.call(10) }
end

$ ruby --version
ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-darwin14]
$ ruby curry.rb
Running each test 65536 times. Test will take about 2 seconds.
klass is faster than λ by 2x ± 0.1
λ is similar to partial
partial is faster than curry by 3x ± 0.1