diff --git a/src/arcaea_offline_ocr/b30/__init__.py b/src/arcaea_offline_ocr/b30/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/arcaea_offline_ocr/b30/chieri/__init__.py b/src/arcaea_offline_ocr/b30/chieri/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/arcaea_offline_ocr/b30/chieri/v4/__init__.py b/src/arcaea_offline_ocr/b30/chieri/v4/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/arcaea_offline_ocr/b30/chieri/v4/colors.py b/src/arcaea_offline_ocr/b30/chieri/v4/colors.py
new file mode 100644
index 0000000..191e0aa
--- /dev/null
+++ b/src/arcaea_offline_ocr/b30/chieri/v4/colors.py
@@ -0,0 +1,37 @@
+import numpy as np
+
+__all__ = [
+    "FONT_THRESHOLD",
+    "PURE_BG_MIN_HSV",
+    "PURE_BG_MAX_HSV",
+    "FAR_BG_MIN_HSV",
+    "FAR_BG_MAX_HSV",
+    "LOST_BG_MIN_HSV",
+    "LOST_BG_MAX_HSV",
+    "BYD_MIN_HSV",
+    "BYD_MAX_HSV",
+    "FTR_MIN_HSV",
+    "FTR_MAX_HSV",
+    "PRS_MIN_HSV",
+    "PRS_MAX_HSV",
+]
+
+FONT_THRESHOLD = 160
+
+PURE_BG_MIN_HSV = np.array([95, 140, 150], np.uint8)
+PURE_BG_MAX_HSV = np.array([110, 255, 255], np.uint8)
+
+FAR_BG_MIN_HSV = np.array([15, 100, 150], np.uint8)
+FAR_BG_MAX_HSV = np.array([20, 255, 255], np.uint8)
+
+LOST_BG_MIN_HSV = np.array([115, 60, 150], np.uint8)
+LOST_BG_MAX_HSV = np.array([140, 255, 255], np.uint8)
+
+BYD_MIN_HSV = (158, 120, 0)
+BYD_MAX_HSV = (172, 255, 255)
+
+FTR_MIN_HSV = (145, 70, 0)
+FTR_MAX_HSV = (160, 255, 255)
+
+PRS_MIN_HSV = (45, 60, 0)
+PRS_MAX_HSV = (70, 255, 255)
diff --git a/src/arcaea_offline_ocr/b30/chieri/v4/ocr.py b/src/arcaea_offline_ocr/b30/chieri/v4/ocr.py
new file mode 100644
index 0000000..dd03488
--- /dev/null
+++ b/src/arcaea_offline_ocr/b30/chieri/v4/ocr.py
@@ -0,0 +1,221 @@
+from datetime import datetime
+from typing import TYPE_CHECKING, List, Optional, Tuple, Union
+
+import attrs
+import cv2
+import numpy as np
+
+from ....crop import crop_xywh
+from ....ocr import preprocess_hog
+from ....types import Mat, XYWHRect, cv2_ml_KNearest
+from ....utils import construct_int_xywh_rect
+from .colors import *
+from .rois import ChieriBotV4Rois
+
+if TYPE_CHECKING:
+    from paddleocr import PaddleOCR
+
+
+@attrs.define
+class ChieriBotV4OcrResultItem:
+    rating_class: int
+    title: str
+    score: int
+    pure: int
+    far: int
+    lost: int
+    date: Union[datetime, str]
+
+
+class ChieriBotV4Ocr:
+    def __init__(
+        self,
+        paddle_ocr: "PaddleOCR",
+        knn_digits_model: cv2_ml_KNearest,
+        factor: Optional[float] = 1.0,
+    ):
+        self.__paddle_ocr = paddle_ocr
+        self.__knn_digits_model = knn_digits_model
+        self.__rois = ChieriBotV4Rois(factor)
+
+    @property
+    def paddle_ocr(self):
+        return self.__paddle_ocr
+
+    @paddle_ocr.setter
+    def paddle_ocr(self, paddle_ocr: "PaddleOCR"):
+        self.__paddle_ocr = paddle_ocr
+
+    @property
+    def knn_digits_model(self):
+        return self.__knn_digits_model
+
+    @knn_digits_model.setter
+    def knn_digits_model(self, knn_digits_model: Mat):
+        self.__knn_digits_model = knn_digits_model
+
+    @property
+    def rois(self):
+        return self.__rois
+
+    @property
+    def factor(self):
+        return self.__rois.factor
+
+    @factor.setter
+    def factor(self, factor: float):
+        self.__rois.factor = factor
+
+    def ocr_component_rating_class(self, component_bgr: Mat) -> int:
+        rating_class_rect = construct_int_xywh_rect(
+            self.rois.component_rois.rating_class_rect
+        )
+        rating_class_roi = crop_xywh(component_bgr, rating_class_rect)
+        rating_class_roi = cv2.cvtColor(rating_class_roi, cv2.COLOR_BGR2HSV)
+        rating_class_masks = [
+            cv2.inRange(rating_class_roi, PRS_MIN_HSV, PRS_MAX_HSV),
+            cv2.inRange(rating_class_roi, FTR_MIN_HSV, FTR_MAX_HSV),
+            cv2.inRange(rating_class_roi, BYD_MIN_HSV, BYD_MAX_HSV),
+        ]  # prs, ftr, byd only
+        rating_class_results = [np.count_nonzero(m) for m in rating_class_masks]
+        if max(rating_class_results) < 70:
+            return 0
+        else:
+            return max(enumerate(rating_class_results), key=lambda i: i[1])[0] + 1
+
+    def ocr_component_title(self, component_bgr: Mat) -> str:
+        # sourcery skip: inline-immediately-returned-variable
+        title_rect = construct_int_xywh_rect(self.rois.component_rois.title_rect)
+        title_roi = crop_xywh(component_bgr, title_rect)
+        ocr_result = self.paddle_ocr.ocr(title_roi, cls=False)
+        title = ocr_result[0][-1][1][0] if ocr_result and ocr_result[0] else ""
+        return title
+
+    def ocr_component_score(self, component_bgr: Mat) -> int:
+        # sourcery skip: inline-immediately-returned-variable
+        score_rect = construct_int_xywh_rect(self.rois.component_rois.score_rect)
+        score_roi = cv2.cvtColor(
+            crop_xywh(component_bgr, score_rect), cv2.COLOR_BGR2GRAY
+        )
+        _, score_roi = cv2.threshold(
+            score_roi, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU
+        )
+        score_str = self.paddle_ocr.ocr(score_roi, cls=False)[0][-1][1][0]
+        score = int(score_str.replace("'", "").replace(" ", ""))
+        return score
+
+    def find_pfl_rects(self, component_pfl_processed: Mat) -> List[List[int]]:
+        # sourcery skip: inline-immediately-returned-variable
+        pfl_roi_find = cv2.morphologyEx(
+            component_pfl_processed,
+            cv2.MORPH_CLOSE,
+            cv2.getStructuringElement(cv2.MORPH_RECT, [10, 1]),
+        )
+        pfl_contours, _ = cv2.findContours(
+            pfl_roi_find, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE
+        )
+        pfl_rects = [cv2.boundingRect(c) for c in pfl_contours]
+        pfl_rects = [
+            r for r in pfl_rects if r[3] > component_pfl_processed.shape[0] * 0.1
+        ]
+        pfl_rects = sorted(pfl_rects, key=lambda r: r[1])
+        pfl_rects_adjusted = [
+            (
+                max(rect[0] - 2, 0),
+                rect[1],
+                min(rect[2] + 2, component_pfl_processed.shape[1]),
+                rect[3],
+            )
+            for rect in pfl_rects
+        ]
+        return pfl_rects_adjusted
+
+    def preprocess_component_pfl(self, component_bgr: Mat) -> Mat:
+        pfl_rect = construct_int_xywh_rect(self.rois.component_rois.pfl_rect)
+        pfl_roi = crop_xywh(component_bgr, pfl_rect)
+        pfl_roi_hsv = cv2.cvtColor(pfl_roi, cv2.COLOR_BGR2HSV)
+
+        # fill the pfl bg with background color
+        bg_point = [round(i) for i in self.rois.component_rois.bg_point]
+        bg_color = component_bgr[bg_point[1]][bg_point[0]]
+        pure_bg_mask = cv2.inRange(pfl_roi_hsv, PURE_BG_MIN_HSV, PURE_BG_MAX_HSV)
+        far_bg_mask = cv2.inRange(pfl_roi_hsv, FAR_BG_MIN_HSV, FAR_BG_MAX_HSV)
+        lost_bg_mask = cv2.inRange(pfl_roi_hsv, LOST_BG_MIN_HSV, LOST_BG_MAX_HSV)
+        pfl_roi[np.where(pure_bg_mask != 0)] = bg_color
+        pfl_roi[np.where(far_bg_mask != 0)] = bg_color
+        pfl_roi[np.where(lost_bg_mask != 0)] = bg_color
+
+        # threshold
+        pfl_roi = cv2.cvtColor(pfl_roi, cv2.COLOR_BGR2GRAY)
+        # get threshold of blurred image, try ignoring the lines of bg bar
+        pfl_roi_blurred = cv2.GaussianBlur(pfl_roi, (5, 5), 0)
+        # pfl_roi_blurred = cv2.medianBlur(pfl_roi, 3)
+        _, pfl_roi_blurred_threshold = cv2.threshold(
+            pfl_roi_blurred, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU
+        )
+        # and a threshold of the original roi
+        _, pfl_roi_threshold = cv2.threshold(
+            pfl_roi, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU
+        )
+        # turn thresholds into black background
+        if pfl_roi_blurred_threshold[2][2] == 255:
+            pfl_roi_blurred_threshold = 255 - pfl_roi_blurred_threshold
+        if pfl_roi_threshold[2][2] == 255:
+            pfl_roi_threshold = 255 - pfl_roi_threshold
+        # return a bitwise_and result
+        result = cv2.bitwise_and(pfl_roi_blurred_threshold, pfl_roi_threshold)
+        result_eroded = cv2.erode(
+            result, cv2.getStructuringElement(cv2.MORPH_CROSS, (2, 2))
+        )
+        return result_eroded if len(self.find_pfl_rects(result_eroded)) == 3 else result
+
+    def ocr_component_pfl(self, component_bgr: Mat) -> Tuple[int, int, int]:
+        try:
+            pfl_roi = self.preprocess_component_pfl(component_bgr)
+            pfl_rects = self.find_pfl_rects(pfl_roi)
+            pure_far_lost = []
+            for pfl_roi_rect in pfl_rects:
+                roi = crop_xywh(pfl_roi, pfl_roi_rect)
+                digit_contours, _ = cv2.findContours(
+                    roi, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE
+                )
+                digit_rects = sorted(
+                    [cv2.boundingRect(c) for c in digit_contours],
+                    key=lambda r: r[0],
+                )
+                digits = []
+                for digit_rect in digit_rects:
+                    digit = crop_xywh(roi, digit_rect)
+                    digit = cv2.resize(digit, (20, 20))
+                    digits.append(digit)
+                samples = preprocess_hog(digits)
+
+                _, results, _, _ = self.knn_digits_model.findNearest(samples, 4)
+                results = [str(int(i)) for i in results.ravel()]
+                pure_far_lost.append(int("".join(results)))
+            return tuple(pure_far_lost)
+        except Exception:
+            return (-1, -1, -1)
+
+    def ocr_component(self, component_bgr: Mat) -> ChieriBotV4OcrResultItem:
+        component_blur = cv2.GaussianBlur(component_bgr, (5, 5), 0)
+        rating_class = self.ocr_component_rating_class(component_blur)
+        title = self.ocr_component_title(component_blur)
+        score = self.ocr_component_score(component_blur)
+        pure, far, lost = self.ocr_component_pfl(component_bgr)
+        return ChieriBotV4OcrResultItem(
+            rating_class=rating_class,
+            title=title,
+            score=score,
+            pure=pure,
+            far=far,
+            lost=lost,
+            date="",
+        )
+
+    def ocr(self, img_bgr: Mat) -> List[ChieriBotV4OcrResultItem]:
+        self.factor = img_bgr.shape[0] / 4400
+        return [
+            self.ocr_component(component_bgr)
+            for component_bgr in self.rois.components(img_bgr)
+        ]
diff --git a/src/arcaea_offline_ocr/b30/chieri/v4/rois.py b/src/arcaea_offline_ocr/b30/chieri/v4/rois.py
new file mode 100644
index 0000000..50c96a2
--- /dev/null
+++ b/src/arcaea_offline_ocr/b30/chieri/v4/rois.py
@@ -0,0 +1,132 @@
+from typing import List, Optional
+
+from ....crop import crop_xywh
+from ....types import Mat, XYWHRect
+from ....utils import apply_factor, construct_int_xywh_rect
+
+
+class ChieriBotV4ComponentRois:
+    def __init__(self, factor: Optional[float] = 1.0):
+        self.__factor = factor
+
+    @property
+    def factor(self):
+        return self.__factor
+
+    @factor.setter
+    def factor(self, factor: float):
+        self.__factor = factor
+
+    @property
+    def top_font_color_detect(self):
+        return apply_factor((35, 10, 120, 100), self.factor)
+
+    @property
+    def bottom_font_color_detect(self):
+        return apply_factor((30, 125, 175, 110), self.factor)
+
+    @property
+    def bg_point(self):
+        return apply_factor((75, 10), self.factor)
+
+    @property
+    def rating_class_rect(self):
+        return apply_factor((21, 40, 7, 20), self.factor)
+
+    @property
+    def title_rect(self):
+        return apply_factor((35, 10, 430, 50), self.factor)
+
+    @property
+    def score_rect(self):
+        return apply_factor((30, 60, 270, 55), self.factor)
+
+    @property
+    def pfl_rect(self):
+        return apply_factor((50, 125, 80, 100), self.factor)
+
+    @property
+    def date_rect(self):
+        return apply_factor((205, 200, 225, 25), self.factor)
+
+
+class ChieriBotV4Rois:
+    def __init__(self, factor: Optional[float] = 1.0):
+        self.__factor = factor
+        self.__component_rois = ChieriBotV4ComponentRois(factor)
+
+    @property
+    def component_rois(self):
+        return self.__component_rois
+
+    @property
+    def factor(self):
+        return self.__factor
+
+    @factor.setter
+    def factor(self, factor: float):
+        self.__factor = factor
+        self.__component_rois.factor = factor
+
+    @property
+    def top(self):
+        return apply_factor(823, self.factor)
+
+    @property
+    def left(self):
+        return apply_factor(107, self.factor)
+
+    @property
+    def width(self):
+        return apply_factor(502, self.factor)
+
+    @property
+    def height(self):
+        return apply_factor(240, self.factor)
+
+    @property
+    def vertical_gap(self):
+        return apply_factor(74, self.factor)
+
+    @property
+    def horizontal_gap(self):
+        return apply_factor(40, self.factor)
+
+    @property
+    def horizontal_items(self):
+        return 3
+
+    @property
+    def vertical_items(self):
+        return 10
+
+    @property
+    def b33_vertical_gap(self):
+        return apply_factor(121, self.factor)
+
+    def components(self, img_bgr: Mat) -> List[Mat]:
+        first_rect = XYWHRect(x=self.left, y=self.top, w=self.width, h=self.height)
+        results = []
+
+        for vi in range(self.vertical_items):
+            rect = XYWHRect(*first_rect)
+            rect += (0, (self.vertical_gap + self.height) * vi, 0, 0)
+            for hi in range(self.horizontal_items):
+                if hi > 0:
+                    rect += ((self.width + self.horizontal_gap), 0, 0, 0)
+                int_rect = construct_int_xywh_rect(rect)
+                results.append(crop_xywh(img_bgr, int_rect))
+
+        rect += (
+            -(self.width + self.horizontal_gap) * 2,
+            self.height + self.b33_vertical_gap,
+            0,
+            0,
+        )
+        for hi in range(self.horizontal_items):
+            if hi > 0:
+                rect += ((self.width + self.horizontal_gap), 0, 0, 0)
+            int_rect = construct_int_xywh_rect(rect)
+            results.append(crop_xywh(img_bgr, int_rect))
+
+        return results
diff --git a/src/arcaea_offline_ocr/ocr.py b/src/arcaea_offline_ocr/ocr.py
index ee24c88..173f850 100644
--- a/src/arcaea_offline_ocr/ocr.py
+++ b/src/arcaea_offline_ocr/ocr.py
@@ -5,6 +5,7 @@ import cv2
 import numpy as np
 from imutils import grab_contours
 from imutils import resize as imutils_resize
+from numpy.linalg import norm
 from pytesseract import image_to_string
 
 from .template import (
@@ -122,6 +123,32 @@ def filter_digit_results(
     return final_result
 
 
+def preprocess_hog(digits):
+    samples = []
+    for img in digits:
+        gx = cv2.Sobel(img, cv2.CV_32F, 1, 0)
+        gy = cv2.Sobel(img, cv2.CV_32F, 0, 1)
+        mag, ang = cv2.cartToPolar(gx, gy)
+        bin_n = 16
+        bin = np.int32(bin_n * ang / (2 * np.pi))
+        bin_cells = bin[:10, :10], bin[10:, :10], bin[:10, 10:], bin[10:, 10:]
+        mag_cells = mag[:10, :10], mag[10:, :10], mag[:10, 10:], mag[10:, 10:]
+        hists = [
+            np.bincount(b.ravel(), m.ravel(), bin_n)
+            for b, m in zip(bin_cells, mag_cells)
+        ]
+        hist = np.hstack(hists)
+
+        # transform to Hellinger kernel
+        eps = 1e-7
+        hist /= hist.sum() + eps
+        hist = np.sqrt(hist)
+        hist /= norm(hist) + eps
+
+        samples.append(hist)
+    return np.float32(samples)
+
+
 def ocr_digits(
     img: Mat,
     templates: TemplateItem,
diff --git a/src/arcaea_offline_ocr/utils.py b/src/arcaea_offline_ocr/utils.py
index e0d8fbd..aa771bf 100644
--- a/src/arcaea_offline_ocr/utils.py
+++ b/src/arcaea_offline_ocr/utils.py
@@ -1,8 +1,11 @@
+from collections.abc import Iterable
+from typing import Callable, Tuple, TypeVar, Union, overload
+
 from cv2 import IMREAD_UNCHANGED, imdecode
 from numpy import fromfile as np_fromfile
 from numpy import uint8
 
-from .types import Mat
+from .types import Mat, XYWHRect
 
 __all__ = ["imread_unicode"]
 
@@ -11,3 +14,34 @@ def imread_unicode(filepath: str) -> Mat:
     # https://stackoverflow.com/a/57872297/16484891
     # CC BY-SA 4.0
     return imdecode(np_fromfile(filepath, dtype=uint8), IMREAD_UNCHANGED)
+
+
+def construct_int_xywh_rect(
+    rect: XYWHRect, func: Callable[[Union[int, float]], int] = round
+):
+    return XYWHRect(*[func(num) for num in rect])
+
+
+@overload
+def apply_factor(item: int, factor: float) -> float:
+    ...
+
+
+@overload
+def apply_factor(item: float, factor: float) -> float:
+    ...
+
+
+T = TypeVar("T", bound=Iterable)
+
+
+@overload
+def apply_factor(item: T, factor: float) -> T:
+    ...
+
+
+def apply_factor(item, factor: float):
+    if isinstance(item, (int, float)):
+        return item * factor
+    elif isinstance(item, Iterable):
+        return item.__class__([i * factor for i in item])