Paper/nms-patches/StatisticManager.patch

--- a/net/minecraft/server/StatisticManager.java
+++ b/net/minecraft/server/StatisticManager.java
@@ -13,6 +13,12 @@
     }
 
     public void b(EntityHuman entityhuman, Statistic<?> statistic, int i) {
+        // CraftBukkit start - fire Statistic events
+        org.bukkit.event.Cancellable cancellable = org.bukkit.craftbukkit.event.CraftEventFactory.handleStatisticsIncrease(entityhuman, statistic, this.getStatisticValue(statistic), i);
+        if (cancellable != null && cancellable.isCancelled()) {
+            return;
+        }
+        // CraftBukkit end
         this.setStatistic(entityhuman, statistic, this.getStatisticValue(statistic) + i);
     }