diff --git a/eventdata/challenges/bulk-size-evaluation.json b/eventdata/challenges/bulk-size-evaluation.json
index ec9d0d5329a37..0cd4c58c36b83 100644
--- a/eventdata/challenges/bulk-size-evaluation.json
+++ b/eventdata/challenges/bulk-size-evaluation.json
@@ -111,5 +111,89 @@
       "clients": {{ p_bulk_indexing_clients }}
     }
   ]
+},
+{
+  "name": "bulk-size-concurrency-evaluation",
+  "description": "Indexes with different bulk sizes and number of connections (2, 20, and 200) while keeping the number of documents in flight constant. IDs are autogenerated by Elasticsearch, meaning there are no conflicts.",
+  "meta": {
+    "benchmark_type": "indexing_bulksize"
+  },
+  "schedule": [
+    {
+      "name": "delete-index-2clients",
+      "operation": "delete-index"
+    },
+    {
+      "name": "create-index-2clients",
+      "operation": {
+        "operation-type": "create-index",
+        "settings": {
+            "index.number_of_replicas": {{ p_replica_count }},
+            "index.number_of_shards": {{ p_shard_count }}
+        }
+      }
+    },
+    {
+      "name": "index-append-1000-2clients",
+      "operation": {
+        "operation-type": "bulk",
+        "param-source": "elasticlogs_bulk",
+        "bulk-size": 1000
+      },
+      "warmup-time-period": 300,
+      "time-period": 600,
+      "clients": 2
+    },
+    {
+      "name": "delete-index-20clients",
+      "operation": "delete-index"
+    },
+    {
+      "name": "create-index-20clients",
+      "operation": {
+        "operation-type": "create-index",
+        "settings": {
+            "index.number_of_replicas": {{ p_replica_count }},
+            "index.number_of_shards": {{ p_shard_count }}
+        }
+      }
+    },
+    {
+      "name": "index-append-100-20clients",
+      "operation": {
+        "operation-type": "bulk",
+        "param-source": "elasticlogs_bulk",
+        "bulk-size": 100
+      },
+      "warmup-time-period": 300,
+      "time-period": 600,
+      "clients": 20
+    },
+    {
+      "name": "delete-index-200clients",
+      "operation": "delete-index"
+    },
+    {
+      "name": "create-index-200clients",
+      "operation": {
+        "operation-type": "create-index",
+        "settings": {
+            "index.number_of_replicas": {{ p_replica_count }},
+            "index.number_of_shards": {{ p_shard_count }}
+        }
+      }
+    },
+    {
+      "name": "index-append-10-200clients",
+      "operation": {
+        "operation-type": "bulk",
+        "param-source": "elasticlogs_bulk",
+        "bulk-size": 10
+      },
+      "warmup-time-period": 300,
+      "time-period": 600,
+      "clients": 200
+    }
+  ]
 }