Fix EP

ep_fix_with_all_plays.R

library(nflscrapR)
library(tidyverse)

# assumes your data is called pbp
pbp <- pbp %>% 
  calculate_expected_points("half_seconds_remaining",
                            "yardline_100",
                            "down",
                            "ydstogo",
                            "goal_to_go")
# change original variables to new calculations, unless new calculations are NA
pbp %<>% mutate(ep = if_else(is.na(ep1), ep, ep1),
                 no_score_prob = if_else(is.na(no_score_prob1), no_score_prob, no_score_prob1),
                 opp_fg_prob = if_else(is.na(opp_fg_prob1), opp_fg_prob, opp_fg_prob1),
                 opp_safety_prob = if_else(is.na(opp_safety_prob1), opp_safety_prob, opp_safety_prob1),
                 opp_td_prob = if_else(is.na(opp_td_prob1), opp_td_prob, opp_td_prob1),
                 fg_prob = if_else(is.na(fg_prob1), fg_prob, fg_prob1),
                 td_prob = if_else(is.na(td_prob1), td_prob, td_prob1),
                 safety_prob = if_else(is.na(safety_prob1), safety_prob, safety_prob1))
# recalculate epa                 
pbp %<>% mutate(epa = lead(ep) - ep)

# there are still possible issues with the original ep on plays where the new ep was NA
# filter those plays out with !is.na(ep)