diff --git a/chain/actors/builtin/power/power.go b/chain/actors/builtin/power/power.go
index e683cfd96d7..8faad718e37 100644
--- a/chain/actors/builtin/power/power.go
+++ b/chain/actors/builtin/power/power.go
@@ -2,6 +2,7 @@ package power
 
 import (
 	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/big"
 	"github.com/ipfs/go-cid"
 	"golang.org/x/xerrors"
 
@@ -60,3 +61,10 @@ type Claim struct {
 	// Sum of quality adjusted power for a miner's sectors.
 	QualityAdjPower abi.StoragePower
 }
+
+func AddClaims(a Claim, b Claim) Claim {
+	return Claim{
+		RawBytePower:    big.Add(a.RawBytePower, b.RawBytePower),
+		QualityAdjPower: big.Add(a.QualityAdjPower, b.QualityAdjPower),
+	}
+}
diff --git a/cmd/lotus-shed/sync.go b/cmd/lotus-shed/sync.go
index bfe7cc8b79e..65d2b6d6f50 100644
--- a/cmd/lotus-shed/sync.go
+++ b/cmd/lotus-shed/sync.go
@@ -2,6 +2,15 @@ package main
 
 import (
 	"fmt"
+	"strconv"
+
+	"github.com/filecoin-project/go-state-types/big"
+
+	"github.com/filecoin-project/lotus/chain/actors/builtin/power"
+
+	"github.com/filecoin-project/go-address"
+
+	"github.com/filecoin-project/go-state-types/abi"
 
 	"github.com/ipfs/go-cid"
 
@@ -16,6 +25,7 @@ var syncCmd = &cli.Command{
 	Flags: []cli.Flag{},
 	Subcommands: []*cli.Command{
 		syncValidateCmd,
+		syncScrapePowerCmd,
 	},
 }
 
@@ -62,3 +72,113 @@ var syncValidateCmd = &cli.Command{
 		return nil
 	},
 }
+
+var syncScrapePowerCmd = &cli.Command{
+	Name:      "scrape-power",
+	Usage:     "given a height and a tipset, reports what percentage of mining power had a winning ticket between the tipset and height",
+	ArgsUsage: "[height tipsetkey]",
+	Action: func(cctx *cli.Context) error {
+		if cctx.Args().Len() < 1 {
+			fmt.Println("usage: <height> [blockCid1 blockCid2...]")
+			fmt.Println("Any CIDs passed after the height will be used as the tipset key")
+			fmt.Println("If no block CIDs are provided, chain head will be used")
+			return nil
+		}
+
+		api, closer, err := lcli.GetFullNodeAPI(cctx)
+		if err != nil {
+			return err
+		}
+
+		defer closer()
+		ctx := lcli.ReqContext(cctx)
+
+		if cctx.Args().Len() < 1 {
+			fmt.Println("usage: <blockCid1> <blockCid2>...")
+			fmt.Println("At least one block cid must be provided")
+			return nil
+		}
+
+		h, err := strconv.ParseInt(cctx.Args().Get(0), 10, 0)
+		if err != nil {
+			return err
+		}
+
+		height := abi.ChainEpoch(h)
+
+		var ts *types.TipSet
+		var startTsk types.TipSetKey
+		if cctx.NArg() > 1 {
+			var tscids []cid.Cid
+			args := cctx.Args().Slice()
+
+			for _, s := range args[1:] {
+				c, err := cid.Decode(s)
+				if err != nil {
+					return fmt.Errorf("block cid was invalid: %s", err)
+				}
+				tscids = append(tscids, c)
+			}
+
+			startTsk = types.NewTipSetKey(tscids...)
+			ts, err = api.ChainGetTipSet(ctx, startTsk)
+			if err != nil {
+				return err
+			}
+		} else {
+			ts, err = api.ChainHead(ctx)
+			if err != nil {
+				return err
+			}
+
+			startTsk = ts.Key()
+		}
+
+		if ts.Height() < height {
+			return fmt.Errorf("start tipset's height < stop height: %d < %d", ts.Height(), height)
+		}
+
+		miners := make(map[address.Address]struct{})
+		for ts.Height() >= height {
+			for _, blk := range ts.Blocks() {
+				_, found := miners[blk.Miner]
+				if !found {
+					// do the thing
+					miners[blk.Miner] = struct{}{}
+				}
+			}
+
+			ts, err = api.ChainGetTipSet(ctx, ts.Parents())
+			if err != nil {
+				return err
+			}
+		}
+
+		totalWonPower := power.Claim{
+			RawBytePower:    big.Zero(),
+			QualityAdjPower: big.Zero(),
+		}
+		for miner := range miners {
+			mp, err := api.StateMinerPower(ctx, miner, startTsk)
+			if err != nil {
+				return err
+			}
+
+			totalWonPower = power.AddClaims(totalWonPower, mp.MinerPower)
+		}
+
+		totalPower, err := api.StateMinerPower(ctx, address.Undef, startTsk)
+		if err != nil {
+			return err
+		}
+
+		qpercI := types.BigDiv(types.BigMul(totalWonPower.QualityAdjPower, types.NewInt(1000000)), totalPower.TotalPower.QualityAdjPower)
+
+		fmt.Println("Number of winning miners: ", len(miners))
+		fmt.Println("QAdjPower of winning miners: ", totalWonPower.QualityAdjPower)
+		fmt.Println("QAdjPower of all miners: ", totalPower.TotalPower.QualityAdjPower)
+		fmt.Println("Percentage of winning QAdjPower: ", float64(qpercI.Int64())/10000)
+
+		return nil
+	},
+}